TWI822355B - Electrostatic chuck and plasma reaction device to improve etching uniformity - Google Patents
Electrostatic chuck and plasma reaction device to improve etching uniformity Download PDFInfo
- Publication number
- TWI822355B TWI822355B TW111136082A TW111136082A TWI822355B TW I822355 B TWI822355 B TW I822355B TW 111136082 A TW111136082 A TW 111136082A TW 111136082 A TW111136082 A TW 111136082A TW I822355 B TWI822355 B TW I822355B
- Authority
- TW
- Taiwan
- Prior art keywords
- dielectric layer
- electrostatic chuck
- wafer
- area
- etching uniformity
- Prior art date
Links
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 57
- 238000005530 etching Methods 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 claims abstract description 22
- 230000008569 process Effects 0.000 claims abstract description 19
- 239000007789 gas Substances 0.000 claims description 18
- 229910010293 ceramic material Inorganic materials 0.000 claims description 10
- 229910052734 helium Inorganic materials 0.000 claims description 10
- 239000001307 helium Substances 0.000 claims description 10
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 10
- 238000001816 cooling Methods 0.000 claims description 6
- 238000005245 sintering Methods 0.000 claims description 5
- 239000011248 coating agent Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 claims description 3
- 230000007797 corrosion Effects 0.000 claims description 3
- 238000005260 corrosion Methods 0.000 claims description 3
- 239000002002 slurry Substances 0.000 claims 1
- 230000005684 electric field Effects 0.000 abstract description 22
- 230000000694 effects Effects 0.000 abstract description 12
- 239000000463 material Substances 0.000 abstract description 7
- 239000010410 layer Substances 0.000 description 122
- 235000012431 wafers Nutrition 0.000 description 88
- 239000003990 capacitor Substances 0.000 description 38
- 238000010586 diagram Methods 0.000 description 12
- 230000007423 decrease Effects 0.000 description 6
- 150000002500 ions Chemical class 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 150000004706 metal oxides Chemical class 0.000 description 4
- 229910052755 nonmetal Inorganic materials 0.000 description 4
- 239000012495 reaction gas Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 239000003989 dielectric material Substances 0.000 description 3
- 230000017525 heat dissipation Effects 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 239000012809 cooling fluid Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000009616 inductively coupled plasma Methods 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000000750 progressive effect Effects 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 206010035148 Plague Diseases 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 241000607479 Yersinia pestis Species 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
Abstract
本發明提供一種提高蝕刻均勻性的靜電吸盤，包含：基座；設置在所述基座上的第一介電層，用於承載晶圓；設置在第一介電層與基座之間的第二介電層，所述第二介電層不同區域的介電常數不相同；通過第二介電層實現按區域調節靜電吸盤的等效電容，使電漿能量沿晶圓的徑向方向的分佈滿足製程要求；所述第二介電層維持所述基座與所述第一介電層之間連續的熱傳導。本發明還提供一種電漿反應裝置。本發明通過改變靜電吸盤本身的材料特性實現改變電場分佈，實現按區域調節晶圓蝕刻速率，有效改善邊緣效應，提高製程均一性。The present invention provides an electrostatic chuck that improves etching uniformity, including: a base; a first dielectric layer provided on the base for carrying a wafer; and an electrostatic chuck provided between the first dielectric layer and the base. The second dielectric layer has different dielectric constants in different areas of the second dielectric layer; through the second dielectric layer, the equivalent capacitance of the electrostatic chuck can be adjusted by area, so that the plasma energy can be adjusted along the radial direction of the wafer. The distribution meets the process requirements; the second dielectric layer maintains continuous heat conduction between the base and the first dielectric layer. The invention also provides a plasma reaction device. The present invention changes the electric field distribution by changing the material characteristics of the electrostatic chuck itself, adjusts the wafer etching rate according to regions, effectively improves the edge effect, and improves the uniformity of the process.
Description
本發明涉及半導體技術領域，特別涉及一種提高蝕刻均勻性的靜電吸盤、電漿反應裝置。The invention relates to the field of semiconductor technology, and in particular to an electrostatic chuck and a plasma reaction device that improve etching uniformity.
在半導體製造技術領域，經常需要在電漿處理裝置內對待處理晶圓進行電漿處理。電漿處理裝置具有一個真空的反應腔，所述反應腔包括一基座，基座上包含一用於放置待處理晶圓的靜電吸盤。In the field of semiconductor manufacturing technology, it is often necessary to perform plasma processing on wafers to be processed in a plasma processing device. The plasma processing device has a vacuum reaction chamber. The reaction chamber includes a base, and the base includes an electrostatic chuck for placing the wafer to be processed.
反應氣體被輸入至反應腔內，大多數電場被包含在待處理晶圓上方的處理區域內，此電場對少量存在於反應腔內部的電子進行加速，使之與輸入的反應氣體的氣體分子碰撞。這些碰撞導致反應氣體的離子化和電漿的激發，從而在反應腔內產生電漿。最後電漿和晶圓之間發生化學反應和/或物理作用（比如蝕刻、沉積等等）形成各種特徵結構。The reaction gas is input into the reaction chamber, and most of the electric field is contained in the processing area above the wafer to be processed. This electric field accelerates a small amount of electrons present inside the reaction chamber, causing them to collide with the gas molecules of the input reaction gas. . These collisions lead to the ionization of the reaction gases and the excitation of the plasma, thereby generating plasma within the reaction chamber. Finally, chemical reactions and/or physical effects (such as etching, deposition, etc.) occur between the plasma and the wafer to form various characteristic structures.
半導體蝕刻中的邊緣效應一直是困擾業界的一個問題。由於電漿受電場強度控制，邊緣處的場強受邊緣條件的影響，部分電場線彎曲導致電場邊緣部分場強不均勻，進而導致電漿密度分部不均。由於晶圓的蝕刻速率與電漿密度相關，因此造成晶圓的徑向蝕刻速率存在差距，從而嚴重影響晶圓的良品率。The edge effect in semiconductor etching has always been a problem that plagues the industry. Since plasma is controlled by the electric field strength, the field strength at the edge is affected by edge conditions. The bending of some electric field lines leads to uneven field strength at the edge of the electric field, which in turn leads to uneven distribution of plasma density. Since the etching rate of the wafer is related to the plasma density, there is a gap in the radial etching rate of the wafer, which seriously affects the yield of the wafer.
隨著晶圓半徑的增大，晶圓徑向蝕刻率的均勻性顯著下降，造成晶圓成品率大大降低。因此，如何簡單有效地調整晶圓表面各區域的電漿能量分佈、提高晶圓製程均一性是業內普遍關心的問題。As the wafer radius increases, the uniformity of the radial etching rate of the wafer decreases significantly, resulting in a significant reduction in the wafer yield. Therefore, how to simply and effectively adjust the plasma energy distribution in each area of the wafer surface and improve the uniformity of the wafer process is a common concern in the industry.
本發明的目的是提供一種提高蝕刻均勻性的靜電吸盤、電漿反應裝置，通過調節靜電吸盤不同區域的介電常數，實現按區域調節靜電吸盤的等效電容，使電漿能量沿晶圓徑向方向的分佈滿足製程要求。本發明通過改變靜電吸盤本身的材料特性以改變電漿密度分佈，實現按區域調節晶圓蝕刻速率，有效改善邊緣效應，提高製程均一性。The purpose of the present invention is to provide an electrostatic chuck and a plasma reaction device that improve etching uniformity. By adjusting the dielectric constant of different areas of the electrostatic chuck, the equivalent capacitance of the electrostatic chuck can be adjusted according to the area, so that the plasma energy can be adjusted along the wafer diameter. The distribution in the direction meets the process requirements. The present invention changes the plasma density distribution by changing the material characteristics of the electrostatic chuck itself, thereby adjusting the wafer etching rate according to regions, effectively improving the edge effect and improving the uniformity of the process.
為了達到上述目的，本發明提供一種提高蝕刻均勻性的靜電吸盤，包含： 基座； 設置在所述基座上的第一介電層，用於承載晶圓； 設置在第一介電層與基座之間的第二介電層，所述第二介電層不同區域的介電常數不相同；通過第二介電層實現按區域調節靜電吸盤的等效電容，使電漿能量沿晶圓徑向方向的分佈滿足製程要求； 所述第二介電層維持所述基座與所述第一介電層之間連續的熱傳導。 In order to achieve the above object, the present invention provides an electrostatic chuck that improves etching uniformity, including: base; a first dielectric layer disposed on the base for carrying the wafer; A second dielectric layer is provided between the first dielectric layer and the base. The dielectric constants of different regions of the second dielectric layer are different; the equivalent of adjusting the electrostatic chuck by region is achieved through the second dielectric layer. Capacitance enables the distribution of plasma energy along the radial direction of the wafer to meet process requirements; The second dielectric layer maintains continuous thermal conduction between the base and the first dielectric layer.
較佳的，所述第二介電層不同區域的介電常數沿著徑向逐漸變大或逐漸變小。Preferably, the dielectric constant of different regions of the second dielectric layer gradually increases or decreases along the radial direction.
較佳的，第二介電層包含中心區域、中部區域、邊緣區域；所述中心區域為與第一介電層同心的圓盤；所述邊緣區域、中部區域為與第一介電層同心的圓環。Preferably, the second dielectric layer includes a central region, a middle region, and an edge region; the center region is a disk concentric with the first dielectric layer; and the edge region and the middle region are concentric with the first dielectric layer. of rings.
較佳的，第二介電層的中部區域的介電常數和第一介電層相同。Preferably, the dielectric constant of the middle region of the second dielectric layer is the same as that of the first dielectric layer.
較佳的，第二介電層的中部區域和第一介電層一體設置。Preferably, the middle region of the second dielectric layer and the first dielectric layer are integrally provided.
較佳的，第二介電層包括多個輔助介電層。Preferably, the second dielectric layer includes a plurality of auxiliary dielectric layers.
較佳的，沿著靜電吸盤的徑向方向，輔助介電層的介電常數逐漸變大或逐漸變小。Preferably, along the radial direction of the electrostatic chuck, the dielectric constant of the auxiliary dielectric layer gradually becomes larger or smaller.
較佳的，具有不同介電常數的至少兩個輔助介電層在垂直方向上層疊佈置。Preferably, at least two auxiliary dielectric layers with different dielectric constants are stacked in a vertical direction.
較佳的，層疊佈置的輔助介電層之間通過黏接或燒結的方式固定。Preferably, the stacked auxiliary dielectric layers are fixed by bonding or sintering.
較佳的，輔助介電層包含有摻雜的陶瓷材質、無摻雜的陶瓷材質、非陶瓷材質中的任意一種或多種。Preferably, the auxiliary dielectric layer includes any one or more of doped ceramic materials, undoped ceramic materials, and non-ceramic materials.
較佳的，第一介電層與晶圓接觸的表面設有多個均勻或非均勻分佈的凸起部。Preferably, the surface of the first dielectric layer in contact with the wafer is provided with a plurality of uniformly or non-uniformly distributed protrusions.
較佳的，基座中設置有多個冷卻管道，所述冷卻管道包含氦氣通道，通過所述氦氣通道將氦氣通至晶圓與第一介電層之間的間隙，且氦氣通道避讓所述凸起部。Preferably, a plurality of cooling pipes are provided in the base, the cooling pipes include helium gas channels, and helium gas is passed through the helium gas channels to the gap between the wafer and the first dielectric layer, and the helium gas The channel avoids the projection.
較佳的，基座的外側壁設有耐電漿腐蝕的鍍膜。Preferably, the outer wall of the base is provided with a coating that is resistant to plasma corrosion.
較佳的，所述提高蝕刻均勻性的靜電吸盤還包含電極；所述電極嵌入設置在第一介電層或第二介電層內，用於產生靜電力。Preferably, the electrostatic chuck for improving etching uniformity further includes an electrode; the electrode is embedded in the first dielectric layer or the second dielectric layer and is used to generate electrostatic force.
較佳的，所述電極的部分區域位於輔助介電層內。Preferably, part of the electrode is located in the auxiliary dielectric layer.
本發明還提供一種電漿反應裝置，包含如本發明所述的靜電吸盤，通過所述靜電吸盤吸附待加工的晶圓。The invention also provides a plasma reaction device, which includes the electrostatic chuck according to the invention, and the wafer to be processed is adsorbed by the electrostatic chuck.
與現有技術相比，本發明的有益效果在於： 1）本發明通過改變靜電吸盤本身的材料特性，使靜電吸盤在不同區域具有不同的等效電容；通過改變靜電吸盤各區域的等效電容，來調節對應區域被加工晶圓表面的電漿能量分佈，實現按區域調節晶圓蝕刻速率，以消除因被加工晶圓表面的電漿能量分佈不均勻而導致的邊緣效應，提高製程均一性，使被加工晶圓獲得理想的製程效果； 2）本發明不受被加工晶圓尺寸的限制，也不受施加在反應腔內上、下電極的射頻電源的頻率限制； 3）本發明無需更換基座，僅通過更換輔助介電層，即可調整靜電吸盤對應區域的等效介電常數，進而調整靜電吸盤對應區域的等效電容；由於輔助介電層更換方便，因而本發明能夠簡單、靈活的調整靜電吸盤各區域的等效電容； 4）本發明通過輔助介電層與第一介電層疊加、多個輔助介電層層疊的方式，在靜電吸盤的各個區域獲得所需的等效介電常數，解決了所需等效介電常數對應的物質不存在或無法應用在靜電吸盤上的問題，提高了電漿能量的調整精度； 5）本發明的輔助介電層具有良好的導熱性，能夠有效地實現熱量在基座與第一介電層之間流通；通過本發明的靜電吸盤能夠快速、有效的調節晶圓表面溫度，實現晶圓表面均溫，保證晶圓加工的製程效果。 Compared with the prior art, the beneficial effects of the present invention are: 1) The present invention changes the material characteristics of the electrostatic chuck itself so that the electrostatic chuck has different equivalent capacitances in different areas; by changing the equivalent capacitance of each area of the electrostatic chuck, the plasma energy on the surface of the processed wafer in the corresponding area is adjusted. Distribution to adjust the wafer etching rate by area to eliminate edge effects caused by uneven distribution of plasma energy on the surface of the wafer being processed, improve process uniformity, and enable the wafer to be processed to obtain ideal process effects; 2) The present invention is not limited by the size of the wafer being processed, nor is it limited by the frequency of the radio frequency power supply applied to the upper and lower electrodes in the reaction chamber; 3) The present invention does not need to replace the base, but only by replacing the auxiliary dielectric layer, the equivalent dielectric constant of the corresponding area of the electrostatic chuck can be adjusted, and then the equivalent capacitance of the corresponding area of the electrostatic chuck can be adjusted; because the auxiliary dielectric layer is easy to replace, Therefore, the present invention can simply and flexibly adjust the equivalent capacitance of each area of the electrostatic chuck; 4) The present invention obtains the required equivalent dielectric constant in each area of the electrostatic chuck by stacking the auxiliary dielectric layer with the first dielectric layer and stacking multiple auxiliary dielectric layers, thereby solving the problem of the required equivalent dielectric constant. The problem that the material corresponding to the electric constant does not exist or cannot be applied to the electrostatic chuck improves the adjustment accuracy of plasma energy; 5) The auxiliary dielectric layer of the present invention has good thermal conductivity and can effectively realize the circulation of heat between the base and the first dielectric layer; the electrostatic chuck of the present invention can quickly and effectively adjust the wafer surface temperature, Achieve uniform temperature on the wafer surface and ensure the process effect of wafer processing.
下面將結合本發明實施例中的附圖，對本發明實施例中的技術方案進行清楚、完整地描述，顯然，所描述的實施例僅僅是本發明一部分實施例，而不是全部的實施例。基於本發明中的實施例，本發明所屬技術領域中的通常知識者在沒有做出具進步性改變的前提下所獲得的所有其他實施例，都屬於本發明保護的範圍。The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the technical field to which the present invention belongs without making any progressive changes shall fall within the scope of protection of the present invention.
圖1示出一種電漿反應裝置的結構示意圖，圖1中的電漿反應裝置為電容耦合電漿（CCP）反應裝置。圖1中的電容耦合電漿反應裝置是一種由施加在基座上的射頻電源通過電容耦合的方式在反應腔內產生電漿並用於蝕刻的設備。其包括真空反應腔100，真空反應腔100包括由金屬材料製成的大致為圓柱形的反應腔側壁101，反應腔側壁101上設置一開口102用於容納晶圓W進出。真空反應腔100內設置一氣體噴淋頭120和一與所述氣體噴淋頭120相對設置的靜電吸盤115，該靜電吸盤115包含一基座110。所述氣體噴淋頭120與一氣體供應裝置125相連，用於向真空反應腔100輸送反應氣體，同時作為真空反應腔100的上電極。基座110作為真空反應腔100的下電極，所述上電極和所述下電極之間形成一反應區域。射頻電源150通過匹配網路152施加到所述下電極，射頻電源160通過匹配網路162施加到所述上電極。在所述上電極和所述下電極之間產生射頻電場，用以將反應氣體解離為電漿，電漿中含有大量的電子、離子、激發態的原子、分子和自由基等活性粒子，上述活性粒子可以和待處理的晶圓W的表面發生多種物理和化學反應，使得晶圓W表面的形貌發生改變，即完成蝕刻過程。真空反應腔100的下方還設置一排氣泵140，用於將反應副產物排出真空反應腔100，維持真空反應腔100的真空環境。Figure 1 shows a schematic structural diagram of a plasma reaction device. The plasma reaction device in Figure 1 is a capacitively coupled plasma (CCP) reaction device. The capacitively coupled plasma reaction device in Figure 1 is a device that uses a radio frequency power supply applied to a base to generate plasma in a reaction chamber through capacitive coupling and is used for etching. It includes a vacuum reaction chamber 100. The vacuum reaction chamber 100 includes a substantially cylindrical reaction chamber side wall 101 made of metal material. An opening 102 is provided on the reaction chamber side wall 101 to accommodate the entry and exit of the wafer W. A gas shower head 120 and an electrostatic chuck 115 arranged opposite to the gas shower head 120 are disposed in the vacuum reaction chamber 100. The electrostatic chuck 115 includes a base 110. The gas shower head 120 is connected to a gas supply device 125 for delivering reaction gas to the vacuum reaction chamber 100 and serving as an upper electrode of the vacuum reaction chamber 100 . The base 110 serves as the lower electrode of the vacuum reaction chamber 100, and a reaction area is formed between the upper electrode and the lower electrode. Radio frequency power 150 is applied to the lower electrode through the matching network 152 , and radio frequency power 160 is applied to the upper electrode through the matching network 162 . A radio frequency electric field is generated between the upper electrode and the lower electrode to dissociate the reaction gas into plasma. The plasma contains a large number of active particles such as electrons, ions, excited atoms, molecules, and free radicals. The above-mentioned The active particles can undergo various physical and chemical reactions with the surface of the wafer W to be processed, causing the morphology of the surface of the wafer W to change, that is, completing the etching process. An exhaust pump 140 is also provided below the vacuum reaction chamber 100 to discharge the reaction by-products out of the vacuum reaction chamber 100 and maintain the vacuum environment of the vacuum reaction chamber 100 .
電漿在對晶圓W進行處理時，由於電漿中的電子和正電離子在品質上存在差異，因而具有不同的運動速度。電子品質小，更容易被電場加速，因而電子具有比正電離子更大的速度。由於一般約束電漿的環境是接地的，如反應腔壁，這樣在電漿和反應腔壁（電位較低）間，運動速度快的電子被接地的反應腔壁導走，而運動速度慢的正電離子就聚集在離反應腔壁一定距離的位置並穩定存在，因此反應腔壁附近產生一個電場，該電場加速正離子、減速電子，通過該電場將由於熱運動的而飛向反應腔壁的電子打回等離子內部。電子和正離子最終穩定了以後，就形成了鞘層結構。同樣原理，晶圓W上方的電漿與晶圓W之間也會形成鞘層結構。When plasma processes wafer W, due to differences in quality between electrons and positively charged ions in the plasma, they have different moving speeds. Electrons have small mass and are more easily accelerated by electric fields, so electrons have a greater speed than positively charged ions. Since the environment that generally confines the plasma is grounded, such as the reaction chamber wall, between the plasma and the reaction chamber wall (low potential), the fast-moving electrons are guided away by the grounded reaction chamber wall, while the slow-moving electrons Positively charged ions gather at a certain distance from the reaction chamber wall and exist stably. Therefore, an electric field is generated near the reaction chamber wall. This electric field accelerates the positive ions and decelerates the electrons. Through this electric field, they will fly towards the reaction chamber wall due to thermal motion. The electrons are knocked back into the plasma. After the electrons and positive ions are finally stabilized, a sheath structure is formed. In the same principle, a sheath structure will also be formed between the plasma above the wafer W and the wafer W.
如圖1所示，上電極的射頻電源160接地（電位固定）、下電極接入的射頻電源150的電位固定，也即上下電極的電位差固定。如圖2所示，射頻場環境下，靜電吸盤115等效為第一電容C1，所述反應區域的電漿和鞘層結構等效為第二電容C2。第一電容C1和第二電容C2串聯在上、下電極之間。理想狀態下，第一電容C1的電壓與第二電容C2的電壓之和等於上、下電極的電位差。第一電容C1、第二電容C2各自所分配的電壓由各自的電容值決定，電容值越大，分配到的電壓越少。電漿密度取決於第二電容分配的電壓，當第二電容C2分配的電壓越高，電漿密度也就越高，晶圓W的蝕刻速率越快。可以通過改變第一電容C1的電容值，實現調整第一電容C1、第二電容C2的所分配的電壓值，達到調整電漿密度的目的。As shown in Figure 1, the radio frequency power supply 160 of the upper electrode is grounded (the potential is fixed), and the potential of the radio frequency power supply 150 connected to the lower electrode is fixed, that is, the potential difference between the upper and lower electrodes is fixed. As shown in Figure 2, in a radio frequency field environment, the electrostatic chuck 115 is equivalent to the first capacitor C1, and the plasma and sheath structure of the reaction area is equivalent to the second capacitor C2. The first capacitor C1 and the second capacitor C2 are connected in series between the upper and lower electrodes. In an ideal state, the sum of the voltage of the first capacitor C1 and the voltage of the second capacitor C2 is equal to the potential difference between the upper and lower electrodes. The voltages distributed by the first capacitor C1 and the second capacitor C2 are determined by their respective capacitance values. The larger the capacitance value, the less voltage is distributed. The plasma density depends on the voltage distributed by the second capacitor C2. When the voltage distributed by the second capacitor C2 is higher, the plasma density is higher, and the etching rate of the wafer W is faster. By changing the capacitance value of the first capacitor C1, the distributed voltage values of the first capacitor C1 and the second capacitor C2 can be adjusted to achieve the purpose of adjusting the plasma density.
易於理解的，第一電容C1的電容值越大，第一電容C1分配到的電壓則越小，從而第二電容C2分配到的電壓越大，反應區域的電漿密度越大。第一電容C1的電容值越小，第一電容分配到的電壓則越大，從而第二電容C2分配到的電壓越小，反應區域的電漿密度越小。It is easy to understand that the greater the capacitance value of the first capacitor C1, the smaller the voltage distributed to the first capacitor C1. Therefore, the greater the voltage distributed to the second capacitor C2, the greater the plasma density in the reaction area. The smaller the capacitance value of the first capacitor C1, the greater the voltage distributed to the first capacitor. Therefore, the smaller the voltage distributed to the second capacitor C2, the smaller the plasma density in the reaction area.
圖1的電漿反應裝置所使用的是普通的靜電吸盤115，圖3、圖3A分別為該靜電吸盤115的剖視圖、俯視圖。普通靜的電吸盤115包含：基座110、設置在基座上的第一介電層111，以及設置在第一介電層111內的電極113。靜電吸盤115通過靜電吸附作用來固定放置在其上的晶圓W。其優點在於吸附作用均勻分佈於晶圓W表面，晶圓W不會發生翹曲變形，對晶圓W無傷害，吸附作用力持續穩定，可以保證晶圓W的加工精度。但使用這種靜電吸盤115的弊端是難以避免晶圓W的邊緣效應。The plasma reaction device in Figure 1 uses a common electrostatic chuck 115. Figures 3 and 3A are respectively a cross-sectional view and a top view of the electrostatic chuck 115. A common electrostatic chuck 115 includes: a base 110, a first dielectric layer 111 disposed on the base, and an electrode 113 disposed in the first dielectric layer 111. The electrostatic chuck 115 fixes the wafer W placed thereon through electrostatic adsorption. Its advantage is that the adsorption force is evenly distributed on the surface of the wafer W, the wafer W will not warp and deform, and there is no harm to the wafer W. The adsorption force is continuously stable, and the processing accuracy of the wafer W can be ensured. However, the disadvantage of using this electrostatic chuck 115 is that it is difficult to avoid the edge effect of the wafer W.
晶圓W的邊緣效應是指電漿處理過程中，上下電極邊緣處的電場的場強受邊緣條件的影響，總有一部分電場線彎曲，導致電場場強不均勻。進而導致電漿密度分佈不均。晶圓W的蝕刻速率隨電漿密度的增加而增加，在這種情況下，必然造成晶圓W的蝕刻速率不均勻，使晶圓內、周邊處理效果產生差異，嚴重時會導致晶圓W良率下降或報廢。The edge effect of wafer W refers to the fact that during plasma processing, the electric field strength at the edges of the upper and lower electrodes is affected by edge conditions. There are always some electric field lines that are bent, resulting in uneven electric field strength. This in turn leads to uneven distribution of plasma density. The etching rate of wafer W increases with the increase of plasma density. In this case, the etching rate of wafer W will inevitably be uneven, causing differences in the processing effects inside and around the wafer. In severe cases, it will cause wafer W Yield drops or scrapped.
圖4顯示了反應腔內使用普通的靜電吸盤115的情況下，在上、下電極分別饋入高頻、甚高頻的射頻能量時，沿晶圓徑向方向的電漿密度分佈曲線。如圖4所示，該靜電吸盤115的半徑為R。在甚高頻的射頻電場下，晶圓中心的電漿密度達到峰值，從晶圓中心至晶圓邊緣，電漿密度逐步降低，降低的幅度大於在高頻的射頻電場下的降低幅度。在高頻的射頻電場下，沿晶圓的徑向方向，晶圓上方電漿的密度先遞增到達一個峰值後，然後遞減。Figure 4 shows the plasma density distribution curve along the radial direction of the wafer when an ordinary electrostatic chuck 115 is used in the reaction chamber and the upper and lower electrodes are fed with high frequency and very high frequency radio frequency energy respectively. As shown in Figure 4, the radius of the electrostatic chuck 115 is R. Under a very high frequency radio frequency electric field, the plasma density in the center of the wafer reaches a peak. From the center of the wafer to the edge of the wafer, the plasma density gradually decreases, and the magnitude of the decrease is greater than that under a high frequency radio frequency electric field. Under a high-frequency radio frequency electric field, along the radial direction of the wafer, the density of plasma above the wafer first increases to a peak, and then decreases.
改變第一電容C1的電容值並不能實現按區域調整電漿密度，因此無法保證晶圓的加工精度。如何按區域調整晶圓上方的電漿密度分佈、提高製程均一性，是本發明需要解決的問題。Changing the capacitance value of the first capacitor C1 cannot adjust the plasma density by area, so the processing accuracy of the wafer cannot be guaranteed. How to adjust the plasma density distribution above the wafer according to regions and improve the uniformity of the process is a problem that needs to be solved by the present invention.
實施例一Embodiment 1
本發明提供一種提高蝕刻均勻性的靜電吸盤，設置在電漿反應裝置的真空反應腔內，如圖5所示，所述靜電吸盤215包含：基座110、第一介電層111、第二介電層112、電極113。The present invention provides an electrostatic chuck that improves etching uniformity, which is arranged in a vacuum reaction chamber of a plasma reaction device. As shown in Figure 5, the electrostatic chuck 215 includes: a base 110, a first dielectric layer 111, a second Dielectric layer 112, electrode 113.
所述第一介電層111設置在基座110上，用於承載晶圓W。所述基座110的外側壁設有耐電漿腐蝕的鍍膜。基座110中設置有多個冷卻管道，所述冷卻管道包含氦氣通道，通過所述氦氣通道將氦氣通至晶圓W與第一介電層111之間的間隙。The first dielectric layer 111 is disposed on the base 110 for carrying the wafer W. The outer side wall of the base 110 is provided with a coating that is resistant to plasma corrosion. A plurality of cooling pipes are provided in the base 110 , and the cooling pipes include helium gas channels through which helium gas is passed to the gap between the wafer W and the first dielectric layer 111 .
本實施例中，如圖5、圖5A所示，第一介電層111為圓盤形，第二介電層112設置在第一介電層111與基座110之間。第二介電層112不同區域的介電常數不相同。通過第二介電層112實現按區域調節靜電吸盤215的等效電容，使電漿能量沿晶圓徑向方向的分佈滿足製程要求。且第二介電層112的上表面與第一介電層111的下表面接觸，第二介電層112的下表面與基座110的上表面接觸，可以實現熱量在基座110與所述第一介電層111之間流通時，在水平面內各方向上比較均勻的分佈，維持基座110與第一介電層111之間連續的熱傳導，第一介電層111和第二介電層112之間也可以通過黏接或燒結的方式固定在一起，以減少之間的縫隙，實現更均勻的熱傳導性。In this embodiment, as shown in FIG. 5 and FIG. 5A , the first dielectric layer 111 is disk-shaped, and the second dielectric layer 112 is disposed between the first dielectric layer 111 and the base 110 . Different regions of the second dielectric layer 112 have different dielectric constants. The equivalent capacitance of the electrostatic chuck 215 is adjusted by region through the second dielectric layer 112 so that the distribution of plasma energy along the radial direction of the wafer meets process requirements. And the upper surface of the second dielectric layer 112 is in contact with the lower surface of the first dielectric layer 111, and the lower surface of the second dielectric layer 112 is in contact with the upper surface of the base 110, so that the heat can be transferred between the base 110 and the base 110. When the first dielectric layer 111 circulates, it is relatively evenly distributed in all directions in the horizontal plane, maintaining continuous heat conduction between the base 110 and the first dielectric layer 111. The first dielectric layer 111 and the second dielectric layer The layers 112 can also be fixed together by bonding or sintering to reduce gaps between them and achieve more uniform thermal conductivity.
本實施例中，如圖5所示，第二介電層112包含中心區域C、邊緣區域E以及位於中心區域C與邊緣區域E之間的中部區域M。所述中心區域C為與第一介電層111同心的圓盤，所述邊緣區域E、中部區域M為與中心區域C同心的圓環。不同區域之間可以通過黏接或燒結的方式固定連接，以消除縫隙，實現更好的熱傳導。根據製程需要，可對上述區域的劃分進行任意調整。例如將蝕刻率低於某一數值的晶圓區域所對應的第二介電層區域作為所述邊緣區域，而非一定要按照數位範圍進行劃分。In this embodiment, as shown in FIG. 5 , the second dielectric layer 112 includes a central region C, an edge region E, and a middle region M located between the central region C and the edge region E. The central region C is a disk concentric with the first dielectric layer 111 , and the edge region E and the middle region M are circular rings concentric with the central region C. Different areas can be fixedly connected by bonding or sintering to eliminate gaps and achieve better heat conduction. According to the needs of the manufacturing process, the division of the above areas can be adjusted arbitrarily. For example, the second dielectric layer area corresponding to the wafer area with an etching rate lower than a certain value is used as the edge area, and does not necessarily need to be divided according to a digital range.
如圖5所示，第二介電層112包括多個輔助介電層116，分別設置在第二介電層112的中心區域C、中部區域M及邊緣區域E。第二介電層112的中心區域C對應的輔助介電層116為圓盤形，其餘的輔助介電層116可以是與第一介電層111同心的圓環。本實施例中，輔助介電層116可以粘接在第一介電層111底面與基座110頂面之間。As shown in FIG. 5 , the second dielectric layer 112 includes a plurality of auxiliary dielectric layers 116 which are respectively disposed in the central region C, the middle region M and the edge region E of the second dielectric layer 112 . The auxiliary dielectric layer 116 corresponding to the central area C of the second dielectric layer 112 is disk-shaped, and the remaining auxiliary dielectric layers 116 may be circular rings concentric with the first dielectric layer 111 . In this embodiment, the auxiliary dielectric layer 116 may be bonded between the bottom surface of the first dielectric layer 111 and the top surface of the base 110 .
輔助介電層116包含：有摻雜的陶瓷材質、無摻雜的陶瓷材質、非陶瓷材質中的任意一種或多種。例如所述有摻雜的陶瓷材質可以是有摻雜的Al 2O 3，其摻雜物包含金屬、非金屬、金屬氧化物、非金屬氧化物中的一種或多種；所述金屬包含Mg或Ti中的至少一種；所述非金屬包含Si；所述金屬氧化物包含MgO或TiO 2中的至少一種；所述非金屬氧化物包含SiO 2。輔助介電層116也可以採用PI （聚醯亞胺，介電常數為3.4），或者石英（介電常數為3.75）等等。中心區域C的輔助介電層116可以是矽（介電常數12）等。 The auxiliary dielectric layer 116 includes any one or more of doped ceramic materials, undoped ceramic materials, and non-ceramic materials. For example, the doped ceramic material may be doped Al 2 O 3 , and its dopant includes one or more of metal, non-metal, metal oxide, and non-metal oxide; the metal includes Mg or At least one of Ti; the non-metal includes Si; the metal oxide includes at least one of MgO or TiO 2 ; the non-metal oxide includes SiO 2 . The auxiliary dielectric layer 116 can also be made of PI (polyimide, dielectric constant is 3.4), or quartz (dielectric constant is 3.75), etc. The auxiliary dielectric layer 116 of the central region C may be silicon (dielectric constant 12) or the like.
圖6為本實施例靜電吸盤的俯視圖。基於第二介電層的分區，靜電吸盤215可以對應地虛擬劃分為中心區域 C’、中部區域 M’與邊緣區域 E’。 Figure 6 is a top view of the electrostatic chuck of this embodiment. Based on the partitioning of the second dielectric layer, the electrostatic chuck 215 can be correspondingly virtually divided into a central area C' , a middle area M' and an edge area E' .
圖7為本實施例中靜電吸盤215的各個區域與其上方電漿、鞘層結構的等效電路圖。如圖7所示，射頻場環境下，將靜電吸盤215等效為分別與中心區域 C’、中部區域 M’與邊緣區域 E’對應的三個電容C11、C12、C13。將靜電吸盤中心區域 C’、中部區域 M’、邊緣區域 E’上方的電漿和鞘層結構，分別等效為與電容C11、C12、C13串聯的三個電容C11、C12、C13。 FIG. 7 is an equivalent circuit diagram of each area of the electrostatic chuck 215 and the plasma and sheath structures above it in this embodiment. As shown in Figure 7, in a radio frequency field environment, the electrostatic chuck 215 is equivalent to three capacitors C11, C12, and C13 corresponding to the central area C' , the middle area M' , and the edge area E' respectively. The plasma and sheath structures above the central area C' , the middle area M' , and the edge area E' of the electrostatic chuck are respectively equivalent to three capacitors C11, C12, and C13 connected in series with the capacitors C11, C12, and C13.
電容C1 i與電容C2 i串聯，電容C1 i與電容C2 i的電壓之和等於上、下電極的電位差（為定值）， i =1,2,3。電容C1 i與電容C2 i各自所分配的電壓由各自的電容值決定，電容值越大，分配到的電壓越少。當電容C1 i的電容值越大，電容C1 i分配到的電壓則越小，從而電容C2 i分配到的電壓越大，靜電吸盤對應區域上方的電漿密度越大。通過按區域調整靜電吸盤的等效電容值（電容C1 i的電容值），實現按區域調整晶圓上方的電漿密度。 Capacitor C1 i and capacitor C2 i are connected in series. The sum of the voltages of capacitor C1 i and capacitor C2 i is equal to the potential difference between the upper and lower electrodes (which is a fixed value), i =1,2,3 . The voltages distributed by the capacitor C1 i and the capacitor C2 i are determined by their respective capacitance values. The larger the capacitance value, the less voltage is distributed. When the capacitance value of capacitor C1 i is larger, the voltage distributed to capacitor C1 i is smaller. Therefore, the voltage distributed to capacitor C2 i is larger, and the plasma density above the corresponding area of the electrostatic chuck is larger. By adjusting the equivalent capacitance value of the electrostatic chuck (the capacitance value of capacitor C1 i ) by region, the plasma density above the wafer can be adjusted by region.
已知電容的電容值C、介電常數 具有以下關係式： ； The capacitance C and dielectric constant of the capacitor are known Has the following relationship: ;
S為電容極板的正對面積，d為電容極板的距離，k是靜電力常量。電容值C隨介電常數 的增大而增大。 S is the facing area of the capacitor plates, d is the distance between the capacitor plates, and k is the electrostatic force constant. The capacitance value C varies with the dielectric constant increases with the increase.
當具有不同介電常數的多種介電材料疊加為一個整體，該整體具有一個新的介電常數，也稱為等效介電常數。本發明中可以根據實際需求，沿第二介電層111的徑向方向，輔助介電層116的介電常數逐漸增大或逐漸減小。使得沿靜電吸盤215的徑向方向，靜電吸盤215的各個區域具有不同的等效介電常數，以調整靜電吸盤各個區域的等效電容值，最終實現調整靜電吸盤各個區域上方的電漿密度。When multiple dielectric materials with different dielectric constants are superimposed into a whole, the whole has a new dielectric constant, also called an equivalent dielectric constant. In the present invention, the dielectric constant of the auxiliary dielectric layer 116 can gradually increase or decrease along the radial direction of the second dielectric layer 111 according to actual requirements. Along the radial direction of the electrostatic chuck 215, each area of the electrostatic chuck 215 has a different equivalent dielectric constant, so as to adjust the equivalent capacitance value of each area of the electrostatic chuck, and ultimately adjust the plasma density above each area of the electrostatic chuck.
如圖7A所示，在甚高頻的射頻電場下，本實施例中靜電吸盤中心區域 C’的半徑為r1。靜電吸盤中部區域 M’的內徑為r1，外徑為r2。靜電吸盤邊緣區域 E’的內徑為r2，外徑為R。 As shown in Figure 7A, under a very high frequency radio frequency electric field, the radius of the central area C' of the electrostatic chuck in this embodiment is r1. The inner diameter of the central area M' of the electrostatic chuck is r1, and the outer diameter is r2. The inner diameter of the edge area E' of the electrostatic chuck is r2, and the outer diameter is R.
如圖5所示，第一介電層111的介電常數為 ，第二介電層111中心區域C、中部區域M、邊緣區域E的輔助介電層116的介電常數分別為 ，其中 。靜電吸盤中心區域 C’、中部區域 M’、邊緣區域 E’的等效介電常數分別等於 。其中， 。因此可以降低靜電吸盤中間區域 C’上方的電漿密度，提高靜電吸盤中部區域 M’、邊緣區域 E’上方的電漿密度，使電漿能量沿晶圓徑向方向的分佈趨同，滿足製程要求。 As shown in FIG. 5 , the dielectric constant of the first dielectric layer 111 is , the dielectric constants of the auxiliary dielectric layer 116 in the central region C, the middle region M, and the edge region E of the second dielectric layer 111 are respectively ,in . The equivalent dielectric constants of the electrostatic chuck center area C' , middle area M' , and edge area E' are respectively equal to . in, . Therefore, the plasma density above the middle area C' of the electrostatic chuck can be reduced, and the plasma density above the middle area M' and edge area E' of the electrostatic chuck can be increased, so that the distribution of plasma energy along the radial direction of the wafer converges to meet the process requirements. .
需要強調的是，本發明通過輔助介電層116與第一介電層111疊加的方式，在靜電吸盤215的各個區域獲得所需的等效介電常數，解決了所需等效介電常數對應的物質不存在或無法應用在靜電吸盤上的問題。It should be emphasized that the present invention obtains the required equivalent dielectric constant in each area of the electrostatic chuck 215 by superimposing the auxiliary dielectric layer 116 and the first dielectric layer 111, thereby solving the problem of the required equivalent dielectric constant. The corresponding material does not exist or cannot be applied to the electrostatic chuck.
製程製程中，晶圓W的散熱相當重要，若無法保證晶圓W表面的均溫，則在晶圓W的製程中無法確保加工的均勻性，晶圓W的加工精度將受到極大的影響。本發明的輔助介電層116具有良好的導熱性，能夠實現熱量在基座110與第一介電層111之間流通。晶圓W的熱量依序通過第一介電層111、輔助介電層116傳遞到基座110，通過基座110內部的冷卻流體有效導走傳遞至基座110的熱量，保證晶圓W表面均溫。During the manufacturing process, the heat dissipation of the wafer W is very important. If the uniform temperature of the surface of the wafer W cannot be guaranteed, the processing uniformity of the wafer W cannot be ensured during the manufacturing process, and the processing accuracy of the wafer W will be greatly affected. The auxiliary dielectric layer 116 of the present invention has good thermal conductivity and can realize heat flow between the base 110 and the first dielectric layer 111 . The heat of the wafer W is transferred to the base 110 through the first dielectric layer 111 and the auxiliary dielectric layer 116 in sequence. The cooling fluid inside the base 110 effectively conducts the heat transferred to the base 110 to ensure that the surface of the wafer W is Uniform temperature.
另有一種調節靜電吸盤對應區域電容的方法：在圖3所示靜電吸盤115的基座110中開有多個空槽，並抽真空。空槽可以看成特殊的介電材料，並通過控制空槽的體積，調整與空槽對應的靜電吸盤115區域的介電常數。空槽的體積越大，靜電吸盤115對應區域的介電常數越小，則靜電吸盤115對應區域的電容越小，靜電吸盤115該區域上方的電漿密度越小。這種方法的弊端是如果想改變靜電吸盤各區域的電容，則每次都需要更換基座110，增加生產成本、降低晶圓W生產效率。另一方面，這種方法會影響晶圓W散熱。基座110通常為金屬材質，具有良好的導熱性。圖3中，晶圓W的熱量由第一介電層111傳遞到基座110中，並通過基座110內部的冷卻流體有效導走該熱量。而基座110內的空槽減少了基座110與第一介電層111的接觸面積（散熱面積），同時由於真空環境的導熱係數低，空槽還降低了基座110的導熱效率。本發明不需要改變基座的現有結構，不僅節約經濟成本，還保證了基座與晶圓之間連續、良好的熱傳導性。There is another method of adjusting the capacitance of the corresponding area of the electrostatic chuck: opening a plurality of empty slots in the base 110 of the electrostatic chuck 115 shown in Figure 3 and vacuuming them. The empty groove can be regarded as a special dielectric material, and by controlling the volume of the empty groove, the dielectric constant of the electrostatic chuck 115 area corresponding to the empty groove can be adjusted. The larger the volume of the empty groove, the smaller the dielectric constant of the corresponding area of the electrostatic chuck 115, the smaller the capacitance of the corresponding area of the electrostatic chuck 115, and the smaller the plasma density above the area of the electrostatic chuck 115. The disadvantage of this method is that if you want to change the capacitance of each area of the electrostatic chuck, you need to replace the base 110 every time, which increases production costs and reduces wafer W production efficiency. On the other hand, this method will affect the heat dissipation of the wafer W. The base 110 is usually made of metal and has good thermal conductivity. In FIG. 3 , the heat of the wafer W is transferred to the base 110 through the first dielectric layer 111 , and the heat is effectively dissipated through the cooling fluid inside the base 110 . The empty slots in the base 110 reduce the contact area (heat dissipation area) between the base 110 and the first dielectric layer 111. At the same time, due to the low thermal conductivity of the vacuum environment, the empty slots also reduce the thermal conductivity efficiency of the base 110. The present invention does not need to change the existing structure of the base, which not only saves economic costs, but also ensures continuous and good thermal conductivity between the base and the wafer.
本發明通過按區域設置不同介電常數的輔助介電層116，實現按區域調整靜電吸盤215的等效介電常數，進而實現按區域調整靜電吸盤215的等效電容值、按區域調整晶圓上方的電漿及鞘層結構的電壓，最後達到按區域調整晶圓上方電漿密度的目的，使電漿能量沿晶圓徑向方向的分佈趨同。靜電吸盤某區域的等效介電常數越高，該區域上方的電漿密度也就越高；靜電吸盤某區域的等效介電常數越低，該區域上方的電漿密度也就越低。By arranging auxiliary dielectric layers 116 with different dielectric constants according to regions, the present invention realizes the adjustment of the equivalent dielectric constant of the electrostatic chuck 215 according to regions, and further realizes the adjustment of the equivalent capacitance value of the electrostatic chuck 215 according to regions and the adjustment of wafers according to regions. The voltage of the upper plasma and sheath structure finally achieves the purpose of adjusting the plasma density above the wafer according to the area, so that the distribution of plasma energy along the radial direction of the wafer converges. The higher the equivalent dielectric constant of a certain area of the electrostatic chuck, the higher the plasma density above that area; the lower the equivalent dielectric constant of a certain area of the electrostatic chuck, the lower the plasma density above that area.
實施例二Embodiment 2
本實施例的靜電吸盤315如圖8所示。第一介電層111與晶圓W接觸的表面還設有多個均勻或非均勻分佈的凸起部117，用於與晶圓W背面組合成氦氣通道，對晶圓進行控溫。The electrostatic chuck 315 of this embodiment is shown in Figure 8 . The surface of the first dielectric layer 111 in contact with the wafer W is also provided with a plurality of uniformly or non-uniformly distributed protrusions 117, which are used to form a helium gas channel with the back surface of the wafer W to control the temperature of the wafer.
如圖8所示，本實施例中第二介電層中部區域M的介電常數和第一介電層111相同。第二介電層中部區域M和第一介電層111一體設置。As shown in FIG. 8 , in this embodiment, the dielectric constant of the middle region M of the second dielectric layer is the same as that of the first dielectric layer 111 . The middle region M of the second dielectric layer and the first dielectric layer 111 are integrally provided.
在高頻的射頻電場下，如圖8A所示，本實施例中靜電吸盤中心區域 C’的半徑為r3。靜電吸盤中部區域 M’的內徑為r3，外徑為r4。靜電吸盤邊緣區域 E’的內徑為r4，外徑為R。 Under a high-frequency radio frequency electric field, as shown in Figure 8A, the radius of the central area C' of the electrostatic chuck in this embodiment is r3. The inner diameter of the central area M' of the electrostatic chuck is r3, and the outer diameter is r4. The inner diameter of the edge area E' of the electrostatic chuck is r4, and the outer diameter is R.
如圖8所示，本實施例中，第一介電層111的介電常數為 ，第二介電層112中心區域C、邊緣區域E的輔助介電層116的介電常數分別為 ，其中 。靜電吸盤中心區域 C’、邊緣區域 E’的等效介電常分別等於F1、F2。其中 。本實施例中通過提高靜電吸盤中心區域 C’、邊緣區域 E’上方的電漿密度，使電漿能量沿晶圓徑向方向的分佈趨同，滿足製程要求。 As shown in FIG. 8 , in this embodiment, the dielectric constant of the first dielectric layer 111 is , the dielectric constants of the auxiliary dielectric layer 116 in the central region C and the edge region E of the second dielectric layer 112 are respectively ,in . The equivalent dielectrics of the central area C' and edge area E' of the electrostatic chuck are often equal to F1 and F2 respectively. in . In this embodiment, by increasing the plasma density above the central area C' and the edge area E' of the electrostatic chuck, the distribution of plasma energy along the radial direction of the wafer is converged to meet the process requirements.
實施例三Embodiment 3
本實施例的靜電吸盤415如圖9所示。為使得靜電吸盤各區域獲得更精確的等效電容（更加精確的等效介電常數），可以將不同介電常數的多個輔助介電層116在垂直方向上層疊佈置。圖9中，第二介電層112的邊緣區域E層疊了兩個介電常數不同的輔助介電層116。層疊的輔助介電層116之間還設有黏接層（圖中未示出），用於固定連接相鄰的輔助介電層116，相鄰的輔助介電層116之間也可以通過燒結的方式結合在一起，可以有更好的導熱性。The electrostatic chuck 415 of this embodiment is shown in Figure 9. In order to obtain a more accurate equivalent capacitance (more accurate equivalent dielectric constant) in each area of the electrostatic chuck, multiple auxiliary dielectric layers 116 with different dielectric constants can be stacked in a vertical direction. In FIG. 9 , two auxiliary dielectric layers 116 with different dielectric constants are stacked on the edge region E of the second dielectric layer 112 . There is also an adhesive layer (not shown in the figure) between the stacked auxiliary dielectric layers 116 for fixed connection between the adjacent auxiliary dielectric layers 116. The adjacent auxiliary dielectric layers 116 can also be connected by sintering. combined together, can have better thermal conductivity.
實施例四Embodiment 4
為更精細化的控制靜電吸盤各區域的等效電容，沿徑向方向，在第二介電層112的中心區域C、中部區域M、邊緣區域E均可以環繞設置多個輔助介電層116。本實施例的靜電吸盤515如圖10所示，第二介電層112的邊緣區域E沿徑向分立設置了兩個介電常數不同的輔助介電層116。In order to more precisely control the equivalent capacitance of each area of the electrostatic chuck, multiple auxiliary dielectric layers 116 can be provided around the central area C, the middle area M, and the edge area E of the second dielectric layer 112 along the radial direction. . As shown in FIG. 10 , the electrostatic chuck 515 of this embodiment has two auxiliary dielectric layers 116 with different dielectric constants separately arranged along the radial direction in the edge region E of the second dielectric layer 112 .
實施例五Embodiment 5
本發明的靜電吸盤還包含電極113。所述電極113連接外部的直流電源，用於產生靜電力。如圖5、圖8所示，電極113可以設置在第一介電層111或第二介電層112內。電極113的設置位置不做限制。當電極113設置在第二介電層112內時，如圖8所示，電極113可以只有部分區域落在輔助介電層116內。The electrostatic chuck of the present invention also includes electrodes 113 . The electrode 113 is connected to an external DC power supply for generating electrostatic force. As shown in FIGS. 5 and 8 , the electrode 113 may be disposed in the first dielectric layer 111 or the second dielectric layer 112 . The installation position of the electrode 113 is not limited. When the electrode 113 is disposed in the second dielectric layer 112, as shown in FIG. 8, only a part of the electrode 113 may fall within the auxiliary dielectric layer 116.
本發明還提供一種電漿反應裝置，如圖11所示，其包含一真空反應腔，該真空反應腔內設有如本發明所述的靜電吸盤，通過所述靜電吸盤吸附待加工的晶圓W。圖11中的電漿反應裝置為電容耦合電漿（CCP）反應裝置，本發明的靜電吸盤同樣適用於電感耦合電漿反應裝置（ICP）。The present invention also provides a plasma reaction device, as shown in Figure 11, which includes a vacuum reaction chamber. The vacuum reaction chamber is provided with an electrostatic chuck as described in the present invention, and the wafer W to be processed is adsorbed by the electrostatic chuck. . The plasma reaction device in Figure 11 is a capacitively coupled plasma (CCP) reaction device, and the electrostatic chuck of the present invention is also suitable for an inductively coupled plasma reaction device (ICP).
本發明通過改變靜電吸盤本身的材料特性，使靜電吸盤在不同區域具有不同的等效電容。通過改變靜電吸盤各區域的等效電容，來調節對應區域被加工晶圓表面的電漿能量分佈，實現按區域調節晶圓W蝕刻速率，以消除因被加工晶圓表面的電漿能量分佈不均勻而導致的邊緣效應，提高製程均一性，使被加工晶圓W獲得理想的製程效果。By changing the material properties of the electrostatic chuck itself, the present invention enables the electrostatic chuck to have different equivalent capacitances in different areas. By changing the equivalent capacitance of each area of the electrostatic chuck, the plasma energy distribution on the surface of the processed wafer is adjusted in the corresponding area, and the wafer W etching rate is adjusted by area to eliminate the inconsistency in plasma energy distribution on the surface of the processed wafer. The edge effect caused by uniformity improves the uniformity of the process and enables the processed wafer W to obtain ideal process effects.
本發明不受被加工晶圓W尺寸的限制，也不受射頻電源的頻率限制。本發明通過輔助介電層116與第一介電層111疊加、多個輔助介電層116層疊的方式，在靜電吸盤的各個區域獲得所需的等效介電常數，解決了所需等效介電常數對應的物質不存在或無法應用在靜電吸盤上的問題，提高了電漿能量的調整精度。The present invention is not limited by the size of the wafer W to be processed, nor is it limited by the frequency of the radio frequency power supply. The present invention obtains the required equivalent dielectric constant in each area of the electrostatic chuck by stacking the auxiliary dielectric layer 116 and the first dielectric layer 111 and stacking multiple auxiliary dielectric layers 116, thereby solving the required equivalent problem. The problem that materials corresponding to dielectric constants do not exist or cannot be applied to electrostatic chucks improves the adjustment accuracy of plasma energy.
本發明無需更換基座110，僅通過更換輔助介電層116，即可調整靜電吸盤對應區域的等效介電常數，進而調整靜電吸盤對應區域的等效電容，且本發明的由於輔助介電層116更換方便快捷。The present invention does not need to replace the base 110, but only by replacing the auxiliary dielectric layer 116, the equivalent dielectric constant of the corresponding area of the electrostatic chuck can be adjusted, and then the equivalent capacitance of the corresponding area of the electrostatic chuck can be adjusted. In addition, due to the auxiliary dielectric Layer 116 can be replaced quickly and easily.
本發明的輔助介電層116具有良好的導熱性，能夠有效地實現熱量在基座110與第一介電層111之間流通；通過本發明的靜電吸盤能夠快速、有效的調節晶圓表面溫度，實現晶圓表面均溫，保證晶圓W加工的製程效果。The auxiliary dielectric layer 116 of the present invention has good thermal conductivity and can effectively realize the flow of heat between the base 110 and the first dielectric layer 111; the electrostatic chuck of the present invention can quickly and effectively adjust the wafer surface temperature. , to achieve uniform temperature on the wafer surface and ensure the process effect of wafer W processing.
以上所述，僅為本發明的具體實施方式，但本發明的保護範圍並不局限於此，任何熟悉本技術領域的技術人員在本發明揭露的技術範圍內，可輕易想到各種等效的修改或替換，這些修改或替換都應涵蓋在本發明的保護範圍之內。因此，本發明的保護範圍應以申請專利範圍的保護範圍為原則。The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of various equivalent modifications within the technical scope disclosed by the present invention. Or replacement, these modifications or replacements should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the patent application.
100:真空反應腔 101:反應腔側壁 102:開口 110:基座 111:第一介電層 112:第二介電層 113:電極 115,215,315,415:靜電吸盤 116:輔助介電層 117:凸起部 120:氣體噴淋頭 125:氣體供應裝置 140:排氣泵 150,160:射頻電源 152,162:匹配網路 C:第二介電層的中心區域 C’:靜電吸盤的中心區域 C1:第一電容 C2:第二電容 E:第二介電層的邊緣區域 E’:靜電吸盤的邊緣區域 M:第二介電層的中部區域 M’:靜電吸盤的中部區域 R:靜電吸盤的半徑 W:晶圓 100: Vacuum reaction chamber 101: Reaction chamber side wall 102:Open your mouth 110:Pedestal 111: First dielectric layer 112: Second dielectric layer 113:Electrode 115,215,315,415:Electrostatic chuck 116: Auxiliary dielectric layer 117:Protruding part 120:Gas sprinkler head 125:Gas supply device 140:Exhaust pump 150,160: RF power supply 152,162: matching network C: Center area of the second dielectric layer C’: The center area of the electrostatic chuck C1: first capacitor C2: second capacitor E: Edge area of the second dielectric layer E’: Edge area of electrostatic chuck M: middle area of the second dielectric layer M’: The middle area of the electrostatic chuck R: Radius of electrostatic chuck W:wafer
為了更清楚地說明本發明技術方案，下面將對描述中所需要使用的附圖作簡單地介紹，顯而易見地，下面描述中的附圖是本發明的一個實施例，對於本發明所屬技術領域中的通常知識者來講，在不付出具進步性改變的前提下，還可以根據這些附圖獲得其他的附圖： 圖1為一種電漿反應裝置示意圖； 圖2為圖1所示電漿反應裝置中，靜電吸盤、電漿及鞘層結構的等效電路圖； 圖3為一種靜電吸盤的剖視圖； 圖3A為圖3所示靜電吸盤的俯視圖； 圖4為高頻、甚高頻的射頻電場下，沿晶圓徑向方向，晶圓上方的電漿密度分佈示意圖； 圖5、圖6為本發明實施例一中，靜電吸盤的剖視圖、俯視圖； 圖7為實施例一中，靜電吸盤各區域與各區域上方電漿、鞘層結構的等效電路圖； 圖7A為實施例一中，在甚高頻射頻電場下，靜電吸盤各區域劃分示意圖； 圖8為本發明實施例二中的靜電吸盤示意圖； 圖8A為實施例二中，在高頻射頻電場下，靜電吸盤各區域劃分示意圖； 圖9為本發明實施例三中的靜電吸盤示意圖； 圖10為本發明實施例四中的靜電吸盤示意圖；以及 圖11為本發明電漿反應裝置的示意圖。 In order to explain the technical solution of the present invention more clearly, the drawings required for the description will be briefly introduced below. Obviously, the drawings in the following description are an embodiment of the present invention. For those in the technical field to which the present invention belongs, To a person with ordinary knowledge, other drawings can be obtained based on these drawings without making any progressive changes: Figure 1 is a schematic diagram of a plasma reaction device; Figure 2 is an equivalent circuit diagram of the electrostatic chuck, plasma and sheath structure in the plasma reaction device shown in Figure 1; Figure 3 is a cross-sectional view of an electrostatic chuck; Figure 3A is a top view of the electrostatic chuck shown in Figure 3; Figure 4 is a schematic diagram of the plasma density distribution above the wafer along the radial direction of the wafer under high-frequency and very high-frequency radio frequency electric fields; Figures 5 and 6 are cross-sectional views and top views of the electrostatic chuck in Embodiment 1 of the present invention; Figure 7 is an equivalent circuit diagram of each area of the electrostatic chuck and the plasma and sheath structures above each area in Embodiment 1; Figure 7A is a schematic diagram of the division of each area of the electrostatic chuck under a very high frequency radio frequency electric field in Embodiment 1; Figure 8 is a schematic diagram of the electrostatic chuck in Embodiment 2 of the present invention; Figure 8A is a schematic diagram of the division of each area of the electrostatic chuck under a high-frequency radio frequency electric field in Embodiment 2; Figure 9 is a schematic diagram of the electrostatic chuck in Embodiment 3 of the present invention; Figure 10 is a schematic diagram of the electrostatic chuck in Embodiment 4 of the present invention; and Figure 11 is a schematic diagram of the plasma reaction device of the present invention.
110:基座 110:Pedestal
111:第一介電層 111: First dielectric layer
112:第二介電層 112: Second dielectric layer
113:電極 113:Electrode
215:靜電吸盤 215:Electrostatic sucker
C:第二介電層的中心區域 C: Center area of the second dielectric layer
E:第二介電層的邊緣區域 E: Edge area of the second dielectric layer
M:第二介電層的中部區域 M: middle area of the second dielectric layer
Claims (16)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111319511.6 | 2021-11-09 | ||
| CN202111319511.6A CN116110840A (en) | 2021-11-09 | 2021-11-09 | Electrostatic chuck and plasma reaction device for improving etching uniformity |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| TW202320218A TW202320218A (en) | 2023-05-16 |
| TWI822355B true TWI822355B (en) | 2023-11-11 |
Family
ID=86256653
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| TW111136082A TWI822355B (en) | 2021-11-09 | 2022-09-23 | Electrostatic chuck and plasma reaction device to improve etching uniformity |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN116110840A (en) |
| TW (1) | TWI822355B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117423716B (en) * | 2023-12-19 | 2024-04-09 | 合肥晶合集成电路股份有限公司 | Back-illuminated semiconductor structure etching method and etching device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20190043746A1 (en) * | 2016-01-27 | 2019-02-07 | Sumitomo Osaka Cement Co., Ltd. | Ceramic material and electrostatic chuck device |
-
2021
- 2021-11-09 CN CN202111319511.6A patent/CN116110840A/en active Pending
-
2022
- 2022-09-23 TW TW111136082A patent/TWI822355B/en active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20190043746A1 (en) * | 2016-01-27 | 2019-02-07 | Sumitomo Osaka Cement Co., Ltd. | Ceramic material and electrostatic chuck device |
Also Published As
| Publication number | Publication date |
|---|---|
| TW202320218A (en) | 2023-05-16 |
| CN116110840A (en) | 2023-05-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI411034B (en) | A plasma processing apparatus and a method and a focusing ring | |
| JP4869610B2 (en) | Substrate holding member and substrate processing apparatus | |
| JP5643528B2 (en) | Substrate processing equipment | |
| JP5759718B2 (en) | Plasma processing equipment | |
| KR100841118B1 (en) | Plasma processing apparatus and plasma processing method | |
| KR102218686B1 (en) | Plasma processing apparatus | |
| US20220223387A1 (en) | High power electrostatic chuck with features preventing he hole light-up/arcing | |
| JP5970268B2 (en) | Plasma processing apparatus and processing method | |
| TWI822355B (en) | Electrostatic chuck and plasma reaction device to improve etching uniformity | |
| US20120222817A1 (en) | Plasma processing apparatus | |
| KR100888807B1 (en) | Apparatus for generating plasma | |
| US20190304754A1 (en) | Plasma processing equipment | |
| CN102299067A (en) | Substrate processing method and substrate processing apparatus | |
| US20230123089A1 (en) | Faceplate having a curved surface | |
| US20240084450A1 (en) | Shower head structure and plasma processing apparatus using the same | |
| JP5602282B2 (en) | Plasma processing apparatus and focus ring and focus ring component | |
| US20220208525A1 (en) | Substrate treating apparatus and substrate treating method | |
| US20140284308A1 (en) | Plasma etching method and plasma etching apparatus | |
| JP5313375B2 (en) | Plasma processing apparatus and focus ring and focus ring component | |
| US20210175051A1 (en) | Edge ring and substrate processing apparatus | |
| JP2022544230A (en) | Chamber configuration for controlled deposition | |
| JP2022533615A (en) | Process chamber with reduced plasma arc | |
| TW202407752A (en) | Electrostatic chuck with continuously adjustable positive and negative voltage and its device and method avoiding the overshoot caused by the close of switch when the voltage applied to a single electrode goes from zero to the output | |
| WO2019042179A1 (en) | Lower electrode assembly and process chamber | |
| JP2007266536A (en) | Plasma treatment apparatus |