1244548 A7 B7 五、發明説明() 5 - 1發明領域: (請先閲讀背面之注意事項再填寫本頁) 本發明係與一種檢測晶圓表面缺陷的方法有關’特别 係有關於一種利用超音波檢測半導體晶圓表面缺陷的方 法。 5 - 2發明背景: 在積體電路的製程中,每個製程的完成度都會影響到 其後續製程的精密度與完善性,從而影響到整個積體電路 的效能。因此在進行重要製程前的檢測程序除了可以對此 片晶圓做必要之改善外,更重要的是能夠確保其後之製程 不會受到此片晶圓的影響,進而全面性的提升製程良率, 以提高生產效率,增加成本效益。所以缺陷檢測實是製程 改進的重要依據。 經濟部智慧財產局員工消費合作社印製 因爲在晶圓製造過程中,常常會在晶圓之邊緣處產生 缺陷,而這些缺陷往往是後續進行製程時破片之原因所 在。因此當一片晶圓要進入半導體元件製程時,通常會先 經過一道檢測程序,將邊緣具缺陷之晶圓挑出,以避免於 後續製程過程產生破片之情形,因爲破片不僅會降低生產 良率,甚至產生之碎片會成爲其他製程晶圓之污染源。因 此如何有效的於進行製程前檢測出具缺陷之晶圓,即成爲 提升製程良率之一大功課。 一般傳統方法均用人工以目視的方法來進行檢 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐) 1244548 A7 B7 五、發明説明() (請先閲讀背面之注意事項再填寫本頁) 測,但此種檢測方式常會因人爲之因素而受影響,如因人 眼睛疲累,因此常常會有檢測品質不穩定之情形發生。且 利用人工之檢測方式,由於人體天生之極限,對於小於1 U m之缺陷常常無法檢測出來。且另一方面,傳統的人 工檢視速度太慢,當晶圓量大時,往往成爲後續製程瓶頸 所在。因此發展出一種快速又有效的檢測方法,即成爲提 升良率之一項重要工作。 5-3發明目的及概述: 鑒於上述之發明背景中,傳統的人工檢測方法,容 易因爲人爲之疏失或因人體天生之極限,而造成檢測結果 的誤判。因此對於一種能不受人爲影響且能依同一檢測標 準進行檢驗之方法具有一種需求。 根據以上所述,爲了減少人爲判斷所發生之檢測標 準不一之現象,增進檢測的效果,本發明提供了一種檢測 半導體製程晶圓缺陷的方法,可以杜絶人爲因素,使因人 眼天生極限無法檢測出之缺陷,在此方法下仍能被檢測出 來。 經濟部智慧財產局員工消費合作社印製 基於上述目的,本發明揭示一種半導體製程中邊緣 缺陷檢測之方法,提供快速及方便之檢測過程。本發明在 進行超音波檢測時,會先以一固定速率旋轉該晶圓,接著 利用超音波之穿透性,使用一超音波發射裝置發射超音波 來掃目苗距離晶圓邊緣6πιιπ之帶狀範圍。一超音波接收裝置 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐) 1244548 五、發明説明() A7 B71244548 A7 B7 V. Description of the invention () 5-1 Field of invention: (Please read the notes on the back before filling out this page) The present invention relates to a method for detecting defects on the surface of a wafer. In particular, it relates to the use of ultrasound Method for detecting semiconductor wafer surface defects. 5-2 Background of the Invention: In the manufacturing process of integrated circuits, the degree of completion of each process will affect the precision and perfection of subsequent processes, and thus affect the efficiency of the entire integrated circuit. Therefore, in addition to making necessary improvements to this wafer, the inspection process before performing important processes is more important to ensure that subsequent processes will not be affected by this wafer, thereby comprehensively improving process yield. To improve production efficiency and increase cost-effectiveness. Therefore, defect detection is an important basis for process improvement. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. During wafer manufacturing, defects often occur at the edges of wafers, and these defects are often the cause of fragmentation during subsequent processing. Therefore, when a wafer is going to enter the semiconductor device process, it usually goes through a testing process to pick out wafers with defective edges to avoid the occurrence of chipping in the subsequent process, because chipping not only reduces the production yield, Even the generated debris can become a source of contamination for other process wafers. Therefore, how to effectively detect defective wafers before the process is one of the major tasks to improve the process yield. Generally, the traditional methods are manual and visual inspection. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 1244548 A7 B7 V. Description of the invention () (Please read the precautions on the back before filling in this Page), but this detection method is often affected by human factors, such as tired eyes, so the quality of the test is often unstable. And using artificial detection methods, due to the natural limits of the human body, defects less than 1 U m are often not detected. On the other hand, the traditional manual inspection speed is too slow. When the wafer volume is large, it often becomes the bottleneck of subsequent processes. Therefore, the development of a fast and effective detection method has become an important task to improve yield. 5-3 Purpose and summary of the invention: In view of the above background of the invention, the traditional manual detection method is easy to cause misjudgment of the detection result due to human error or the natural limit of the human body. Therefore, there is a need for a method that can be free from human influence and can be tested according to the same detection standard. According to the above, in order to reduce the artificial detection of different detection standards and improve the detection effect, the present invention provides a method for detecting wafer defects in a semiconductor process, which can eliminate human factors and cause human eyes. Defects that cannot be detected by natural limits can still be detected under this method. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Based on the above-mentioned purpose, the present invention discloses a method for detecting edge defects in a semiconductor process, providing a fast and convenient detection process. In the ultrasonic detection of the present invention, the wafer is first rotated at a fixed rate, and then the ultrasonic penetrability is used, and a ultrasonic transmitting device is used to emit an ultrasonic wave to sweep the seedlings into a strip shape 6πιππ away from the wafer edge range. An ultrasonic receiving device This paper size is applicable to China National Standard (CNS) A4 specification (210X297 mm) 1244548 V. Description of invention () A7 B7
嘗接收掃瞄後之超音 心时才別記綠超音波發射裝置與 接收裝置在接收與發射時所得的強度,即可根據發射時與 接收時超音波能量差異檢測出掃瞄區域内 在:本發明之方法可分辨缺陷大小,最後亦可根據對二: 所仔結果之分析進行製程改善,達到檢測的目的。 5-4圖式簡單説明: 由以下本發明中較佳具體實施例之細節描述’可以 對本發明之目的、觀點及優點有更佳的了解。同時參考下 列本發明之圖式加以說明: 第一圖所示為晶圓上視圖。 弟一圖所示為為一晶圓缺陷概略圖。 第三圖所示為根據本發明利用超音波檢測晶圓缺陷 所製造檢測系統部分元件剖面示意圖。 閱第四圖所示為利用本發明之方法掃晦半導體晶圓 所得到之波形圖。 5 - 5圖號對照說明: (請先閲讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 1 00半導體晶圓 2〇2 , 204 晶圓缺陷 304超音波發射裝置 308超音波 1 0 2凹入區域 302旋轉裝置 306超音波接收裝置 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐) 1244548 A7 B7 五、發明説明() 5 - 6發明詳細說明: (請先閲讀背面之注意事項再填寫本頁) 在不限制本發明之精神及應用範圍之下,以下即以 一實施例,介紹本發明之實施;熟悉此領域技藝者,在瞭 解本發明之精神後,當可應用此種超音波檢測缺陷方法於 各種不同之晶圓檢測製程中。藉由本發明之方法,一旦發 現要進行製程之某一晶圓,其缺陷大小與缺陷數目超出後 續製程可接受值,則可以在晶圓進行投產製程前,即時將 此片晶圓抽出,避免於後續製程中產生破片,甚而成為其 他製程晶圓之污染源。同時本發明之方法,可杜絕人為因 素,改善傳統的人工檢測方法,容易因爲人爲之疏失或因 人體天生之極限,而造成檢測結果的誤判能,使得檢測均 能依同一檢測標準進行。本發明之應用當不僅限於以下所 述之實施例。 經濟部智慧財產局員工消費合作社印製 參閱第一圖,為一晶圓100之上視圖,其中凹入區 域1 0 2為此晶圓在進行對準時之所使用對準點。當晶圓經 由拉伸成長並切割完成後,通常會在經過一晶邊圓磨之步 驟,其主要原因在於當進行沈積成長時,銳角區域之成長 速率會較平面為高,因此若使用未經圓磨之晶圓容易在邊 緣產生凸起。同樣的,晶圓圓磨亦可防止熱應力之集中, 避免於晶圓之邊緣產生差排等材料缺陷。然而這種晶邊圓 磨之過程,卻常常會在圓磨區域留下缺陷。 請參閱第二圖所示為一晶圓缺陷概略圖,其為經由 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐) 經濟部智慧財產局員工消費合作社印製 1244548 A7 _ B7 五、發明説明() 第一圖之AA{看入之晶圓側視圖,當晶圓經過一晶邊圓磨步 驟後,常會在圓磨區域,留下大小不一之缺陷,有的位於 圓磨區域之表面,如缺陷2〇2,有的會深入圓磨區域内, 如缺陷20 4。這些缺陷常常會造成晶圓之破碎。 請參照第二圖,其所繪示為本發明利用超音波檢測 晶圓缺陷所製造檢測系統部分元件剖面示意圖。以本系統 而言,當進行晶圓表面檢測時,首先會先將待測晶圓丨〇 〇, 放置於一旋轉裝置302上,此晶圓固定於旋轉裝置上之方 法,可利用吸氣之方式,或其他等同之方法。接著此旋轉 裝置3 0 2會以一疋之速度開始旋轉,其速度以八吋晶圓為 例,通常為5至10秒讓此晶圓旋轉一週。而在晶圓邊緣處 會架ax —超音波發射裝置3〇4與超音波接收裝置3〇6,以 本最佳實施例而言,此超音波之檢測範圍為從邊緣朝向中 心點約6mm之帶狀範圍,由於檢測時此晶圓是處於旋轉狀 態,因此總檢測區域為環繞該晶圓且距邊緣6mm之環狀範 圍。所謂超音波為音之振動,即謂在彈性媒質(如空氣) 中之疏密振動,其頻率遠超出人聽覺界線,約在2〇KHz以 上之範圍。 s進行晶圓缺陷檢測時,超音波發射裝置3 〇 4會以 -定頻率發射出-超音;皮3G8,以本最佳實施例而言,此 發射出之超音波頻率為3MHz。而超音波接收裝置3〇6,用 來接收超音波發射裝置304所發射出之超音波。由於超音 波具穿透性,當晶圓表面未具任何之缺陷時,此時超音波 於發射裝置304與接收裝置30 6間相對振幅並不會發生變 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐) ..............·裝:-......訂......... - (請先閱讀背面之注意事項再填寫本頁) 1244548 A7 B7 五、發明説明() 化,亦即,其能量除了稍具衰減並不會造成很大之改變。 此時分别記錄超音波發射裝置與接收裝置在接收與發射時 所得的強度,利用下式可得一比値。 (請先閲讀背面之注意事項再填寫本頁) ,接收二y /輸出」 根據發射時與接收時超音波能量之比值差異即可檢 測出掃瞄區域内是否有缺陷存在。當掃瞄區域内未有缺陷 存在時,上述之比值A將為一常數。然而當掃瞄區域内存 有缺陷時,當超音波掃瞄到此缺陷區域時,於接收裝置所 接收之超音波能量(振幅)會有衰減情況發生,造成上述 之比值A會從原本之常數值下降,因此即可得知此區域内 有缺陷存在。且依照本發明之方法,超音波之發射裝置與 接收裝置在進行掃瞄之過程中並不需要碰觸到晶圓,因 此,不會污染到晶圓。 經濟部智慧財產局員工消費合作社印製 參閱第四圖,為利用本發明之方法,使用頻率3MHz 之超音波,掃瞄距半導體晶圓邊緣6mm環狀帶區域,且此 半導體晶圓以0 · 1至1轉/秒速率進行旋轉,所得到之波形 圖。其中此圖之縱軸為波幅,橫軸為徑長。從圖中可明顯 看出,當超音波掃瞄到缺陷時,此波形圖會有下降之情況 發生。且由於此半導體晶圓是以固定速率進行旋轉,因此 根據比例關係,從下降發生之時間長短,即可得出此缺陷 之大小。 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐) 1244548 A7 B7 五、發明説明() 本發明方法的特色之一,在於將傳統上均使用人工 檢驗晶圓之方式,改以超音波之方式來進行,以將傳統上 人為影響之因素降至最低用。此外,長久以來利用人工檢 驗之人士,均未能思及利用超音波之方式,不但可以檢驗 出缺陷,甚至能得知缺陷之大小,足見本發明有進步之處。 本發明以較佳實施例說明如上,僅用於藉以幫助了 解本發明之實施,非用以限定本發明之精神,而熟悉此領 域技藝者於領悟本發明之精神後,在不脫離本發明之精神 範圍内,當可做些許更動潤飾及等同之變化替換,其專利 保護範圍當視後附之專利申請範圍及其等同領域而定。 (請先閲讀背面之注意事項再填寫本頁) 、τ 經濟部智慧財產局員工消費合作社印製 本紙張尺度適用中國國家標準(CNS)A4規格(210X297公釐)Do n’t remember the intensity obtained by the green ultrasonic transmitting device and the receiving device during receiving and transmitting when you try the ultrasonic heart after receiving the scan. The inherent scanning area can be detected based on the difference between the ultrasonic energy during transmitting and receiving: the invention The method can distinguish the size of the defect, and finally, the process can be improved based on the analysis of the results of the two: to achieve the purpose of inspection. 5-4 Schematic description: The object, viewpoint, and advantages of the present invention can be better understood from the following detailed description of the preferred embodiments of the present invention. At the same time, it is explained with reference to the following drawings of the present invention: The first figure shows a top view of a wafer. Figure 1 shows a schematic diagram of a wafer defect. The third figure is a schematic cross-sectional view of some components of an inspection system manufactured by using ultrasonic to detect wafer defects. The fourth figure is a waveform diagram obtained by obscuring a semiconductor wafer using the method of the present invention. 5-5 drawing number comparison instructions: (Please read the notes on the back before filling out this page) Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs, the Consumer Cooperatives printed 100 semiconductor wafers, 202, 204 wafer defects, 304 ultrasonic emission device, 308 Ultrasonic 1 0 2 recessed area 302 rotating device 306 ultrasonic receiving device This paper size is applicable to Chinese National Standard (CNS) A4 specification (210X297 mm) 1244548 A7 B7 V. Description of invention () 5-6 Detailed description of the invention: ( Please read the notes on the back before filling this page.) Without limiting the spirit and scope of the invention, the following is an example to introduce the implementation of the invention; those skilled in the art will understand the spirit of the invention Later, this ultrasonic inspection defect method can be applied in various wafer inspection processes. With the method of the present invention, once a wafer to be processed is found to have a defect size and number of defects that exceeds the acceptable values of subsequent processes, the wafer can be extracted immediately before the wafer is put into production, avoiding Fragments are generated in subsequent processes and even become a source of contamination for other process wafers. At the same time, the method of the present invention can eliminate human factors, improve the traditional manual detection method, and easily cause misjudgment of detection results due to human errors or natural limits of the human body, so that the detection can be performed according to the same detection standard. The application of the present invention is not limited to the embodiments described below. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Refer to the first figure, which is a top view of a wafer 100, in which the recessed area 102 is the alignment point used when the wafer is aligned. After the wafer is grown by stretching and slicing, it usually goes through a crystal edge round grinding step. The main reason is that when depositing and growing, the growth rate of the acute angle area is higher than that of the flat surface. Rounded wafers are prone to bumps on the edges. Similarly, wafer round grinding can also prevent the concentration of thermal stress and avoid material defects such as differential rows at the edges of the wafer. However, the process of round grinding of crystal edges often leaves defects in the rounded area. Please refer to the second figure for a schematic diagram of a wafer defect, which is printed on this paper scale to the Chinese National Standard (CNS) A4 specification (210X297 mm). Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. 、 Explanation of the invention () AA {The side view of the wafer as seen in the first picture. After the wafer is subjected to a round grinding step, it often leaves defects of different sizes in the round grinding area, and some are located in the round grinding. The surface of the area, such as defect 002, may penetrate deeply into the rounded area, such as defect 20 4. These defects often cause wafer breakage. Please refer to the second figure, which is a schematic cross-sectional view of some components of an inspection system manufactured by using the ultrasonic to detect wafer defects in the present invention. In terms of this system, when performing wafer surface inspection, the wafer to be tested is first placed on a rotating device 302. The method of fixing the wafer to the rotating device can be obtained by using the suction method. Method, or other equivalent methods. Then the rotating device 3 02 will start to rotate at a speed of one second. The speed is an eight-inch wafer, for example, usually 5 to 10 seconds to make the wafer rotate one revolution. At the edge of the wafer, ax—an ultrasonic transmitting device 304 and an ultrasonic receiving device 306 are set. In the preferred embodiment, the detection range of this ultrasonic wave is about 6mm from the edge toward the center point. Band-shaped range. Because the wafer is in a rotating state during inspection, the total inspection area is a ring-shaped range that surrounds the wafer and is 6 mm from the edge. The so-called ultrasonic vibration is the vibration of sound, that is, the dense vibration in the elastic medium (such as air), whose frequency is far beyond the human hearing boundary, which is about 20KHz or more. When wafer defect detection is performed, the ultrasonic transmitting device 304 will emit ultrasonic at a fixed frequency; for the 3G8, in the present preferred embodiment, the ultrasonic frequency emitted by this is 3 MHz. The ultrasonic receiving device 306 is used to receive the ultrasonic waves emitted by the ultrasonic transmitting device 304. Due to the ultrasonic penetrability, when there is no defect on the surface of the wafer, the relative amplitude of the ultrasonic wave between the transmitting device 304 and the receiving device 306 will not change at this time. A4 size (210X297mm) .............. Packing: -...... Order ...-(Please read the precautions on the back first (Fill in this page again) 1244548 A7 B7 5. Description of the invention (), that is, its energy will not cause great changes except for a slight attenuation. At this time, the strengths obtained by the ultrasonic transmitting device and the receiving device during reception and transmission are recorded separately, and a comparison can be obtained by using the following formula. (Please read the precautions on the back before filling out this page). Receiving two y / output "According to the difference of the ultrasonic energy ratio between transmitting and receiving, you can detect whether there are defects in the scanning area. When there are no defects in the scanning area, the above-mentioned ratio A will be a constant. However, when there is a defect in the scanning area, when the ultrasonic wave is scanned to the defective area, the ultrasonic energy (amplitude) received by the receiving device will be attenuated, causing the above-mentioned ratio A to change from the original constant value It can be known that there are defects in this area. In addition, according to the method of the present invention, the ultrasonic transmitting device and the receiving device do not need to touch the wafer during the scanning process, so the wafer is not polluted. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, referring to the fourth figure, in order to use the method of the present invention, using a ultrasonic wave with a frequency of 3 MHz, scanning a 6 mm ring zone from the edge of a semiconductor wafer, The waveform is obtained by rotating at a speed of 1 to 1 revolutions per second. The vertical axis of this figure is the amplitude, and the horizontal axis is the diameter. It is obvious from the figure that when the ultrasound scans the defect, the waveform will drop. And because this semiconductor wafer rotates at a fixed rate, according to the proportional relationship, the size of this defect can be obtained from the length of time that the decline occurred. This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 1244548 A7 B7 V. Description of the invention () One of the features of the method of the present invention is that the traditional method of manually inspecting wafers is changed to The sonic method is used to minimize the traditional human factors. In addition, people who have used manual inspection for a long time have failed to consider the use of ultrasonic waves. Not only can they detect defects, they can even know the size of the defects, which shows that the invention has made progress. The present invention is described above with the preferred embodiments, and is only used to help understand the implementation of the present invention, and is not intended to limit the spirit of the present invention. Those skilled in the art will not depart from the present invention after understanding the spirit of the present invention. Within the scope of the spirit, when some modifications and equivalent changes can be made, the scope of patent protection shall depend on the scope of the attached patent application and its equivalent fields. (Please read the precautions on the back before filling this page), τ Printed by the Consumer Cooperatives of Intellectual Property Bureau of the Ministry of Economic Affairs This paper size applies to China National Standard (CNS) A4 (210X297 mm)