TWI523145B

TWI523145B - Bond pad structure and fabricating method thereof

Info

Publication number: TWI523145B
Application number: TW100137173A
Authority: TW
Inventors: 吳惠敏; 王銘義; 王冠宇; 謝坤哲; 黃建欣
Original assignee: 聯華電子股份有限公司
Priority date: 2011-10-13
Filing date: 2011-10-13
Publication date: 2016-02-21
Also published as: TW201316455A

Description

銲墊結構及其製作方法Pad structure and manufacturing method thereof

本發明是有關於一種半導體元件及其製作方法，且特別是有關於一種元件的銲墊結構及其製作方法。The present invention relates to a semiconductor device and a method of fabricating the same, and more particularly to a pad structure for an element and a method of fabricating the same.

隨著科技的進步，消費性電子產品不斷地朝向小型化發展，同時其效能與功能亦不斷地在提升，各類型的消費性電子產品如行動電話、筆記型電腦、MP3播放器與個人數位助理(PDA)等產品不斷地朝向輕薄短小、強大功能與低成本的方向演進。為滿足上述需求，遂發展出微電機構系統元件(Micro-Electro-Mechanical System，MEMS)元件，例如微聲波感測器(micro-acoustical sensor)、微陀螺儀感測器(Micro-gyro sensor感測器)、加速度感測器(accelerometer)或時脈產生及震盪器(clock generation and oscillator)。With the advancement of technology, consumer electronics products are constantly moving toward miniaturization, and their performance and functions are constantly improving. Various types of consumer electronics such as mobile phones, notebook computers, MP3 players and personal digital assistants Products such as (PDA) are constantly evolving toward thin, short, powerful and low-cost. In order to meet the above requirements, we have developed Micro-Electro-Mechanical System (MEMS) components such as micro-acoustical sensors and micro-gyro sensors. Detector), accelerometer or clock generation and oscillator.

典型的微電機構件，係採用半導體製程，將複數個微機電元件，直接微小化地形成在晶圓表面，並藉由銲墊及導線與處理或傳遞微機電元件之訊號的電子電路加以整合，之後再藉由晶粒切割(die sawing)。A typical micro-motor component uses a semiconductor process to form a plurality of MEMS components directly on the surface of the wafer and integrate them with electronic circuits that process or transmit signals from the MEMS components. It is then die sawing.

然而，由於一般銲墊和微電機構件都需要在晶圓表面形成開口。因此當銲墊開口形成之後，常會受到形成微電機構件開口的蝕刻製程影響，而對銲墊的開口產生側蝕(undercut)，導致銲墊容易因後續製程步驟，例如晶粒切割製程，所產生的應力衝擊，而產生脫層(material peeling)的現象。However, since both the pad and the micro-motor component require an opening on the surface of the wafer. Therefore, when the pad opening is formed, it is often affected by an etching process for forming the opening of the micro-motor component, and an undercut is generated on the opening of the pad, which causes the pad to be easily generated by subsequent process steps such as a die cutting process. The stress is impacted, resulting in a phenomenon of material peeling.

因此如何防止微電機構系統元件的銲墊不受後續製程的應力破壞，仍是業界亟待解決的問題。Therefore, how to prevent the solder pads of the components of the micro-electric system from being damaged by the stress of the subsequent process is still an urgent problem to be solved in the industry.

有鑑於此，本發明的目的之一，就是在提供一種銲墊結構，包括：內連線結構以及覆蓋隔離層。其中，內連線結構具有至少一個開口和至少一個金屬銲墊。覆蓋隔離層，位於內連線結構之上，並延伸覆蓋開口的側壁，而與金屬銲墊接觸，使一部份的金屬銲墊由開口暴露於外。In view of the above, one of the objects of the present invention is to provide a pad structure including: an interconnect structure and a cover spacer. Wherein, the interconnect structure has at least one opening and at least one metal pad. The cover layer is over the interconnect structure and extends over the sidewalls of the opening to contact the metal pads such that a portion of the metal pads are exposed from the openings.

在本發明之一實施例中，構成覆蓋隔離層的材質，係選自於由氧化鋁(Al₂O₃)、氮化矽(SiN)、非晶矽(amorphous silicon)、氮碳化矽(SiCN)、有機聚合物或上述任意組合所組成之一族群。在本發明之一實施例中，覆蓋隔離層具有一個導角，形成於開口的側壁與金屬銲墊鄰接的位置上。In an embodiment of the invention, the material constituting the cover layer is selected from the group consisting of alumina (Al ₂ O ₃ ), tantalum nitride (SiN), amorphous silicon, and niobium nitriding (SiCN). ), an organic polymer or a combination of any of the above. In one embodiment of the invention, the cover spacer has a lead angle formed at a location adjacent the sidewall of the opening to the metal pad.

在本發明之一實施例中，內連線結構包括內層介電層以及鈍化層。其中，內層介電層用來承或金屬銲墊；鈍化層(passivation layer)則覆蓋於內層介電層上，而開口則係穿透鈍化層，將一部份的金屬銲墊暴露於外。In an embodiment of the invention, the interconnect structure includes an inner dielectric layer and a passivation layer. Wherein, the inner dielectric layer is used to support or the metal pad; the passivation layer covers the inner dielectric layer, and the opening penetrates the passivation layer to expose a portion of the metal pad to outer.

在本發明之一實施例中，銲墊結構更包括：位於覆蓋隔離層上，且不與金屬銲墊接觸的硬罩幕層。在本發明之一實施例中，硬罩幕層係一鋁金屬層。在本發明之一實施例中，銲墊結構更包括包埋於覆蓋隔離層與該硬罩幕層之間的二氧化矽層。在本發明之一實施例中，銲墊結構更包括，形成於與開口同側，但未暴露於外之金屬銲墊表面上的金屬氧化層。In an embodiment of the invention, the pad structure further comprises: a hard mask layer on the cover spacer layer and not in contact with the metal pad. In one embodiment of the invention, the hard mask layer is an aluminum metal layer. In an embodiment of the invention, the pad structure further includes a ceria layer embedded between the cover spacer layer and the hard mask layer. In an embodiment of the invention, the pad structure further includes a metal oxide layer formed on the same side of the opening but not exposed to the surface of the outer metal pad.

本發明的另一目的，就是在提供一種微電機構系統元件(Micro-Electro-Mechanical System，MEMS)，包括：基材以及形成於基材之上的電晶體元件、微電機構件和銲墊結構。而銲墊結構包括：內連線結構以及覆蓋隔離層。內連線結構形成於基材之上，具有至少一個開口和至少一個與電晶體元件和微電機構件電性連結的金屬銲墊。覆蓋隔離層位於內連線結構之上，並延伸覆蓋開口的側壁，而與金屬銲墊接觸，且使一部份金屬銲墊由開口暴露於外。Another object of the present invention is to provide a Micro-Electro-Mechanical System (MEMS) comprising: a substrate and a transistor element, a micro-motor component and a pad structure formed on the substrate . The pad structure includes: an interconnect structure and a cover isolation layer. The interconnect structure is formed over the substrate and has at least one opening and at least one metal pad electrically coupled to the transistor component and the micromachine component. The cover spacer is over the interconnect structure and extends over the sidewall of the opening to contact the metal pad and expose a portion of the metal pad from the opening.

在本發明之一實施例中，微電機構系統元件更包括位於覆蓋隔離層上，且不與金屬銲墊接觸的硬罩幕層。在本發明之一實施例中，覆蓋隔離層具有一個導角，形成於開口的側壁與金屬銲墊鄰接的位置上方。在本發明之一實施例中，微電機構系統元件更包括：包埋於覆蓋隔離層與硬罩幕層之間的二氧化矽層。在本發明之一實施例中，微電機構系統元件更包括一個金屬氧化層，形成於金屬銲墊與開口同側，但未暴露於外的表面上。In one embodiment of the invention, the micro-electrical system component further includes a hard mask layer overlying the isolation barrier and not in contact with the metal pads. In one embodiment of the invention, the cover spacer has a lead angle formed above the sidewall of the opening adjacent the metal pad. In an embodiment of the invention, the micro-electric system component further includes: a ceria layer embedded between the cover isolation layer and the hard mask layer. In one embodiment of the invention, the micro-electric system component further includes a metal oxide layer formed on the same side of the metal pad as the opening but not exposed to the outer surface.

本發明的又一目的，就是在提供一種銲墊結構的製造方法，包括下述步驟：首先提供具有內層介電層和至少一金屬銲墊的內連線結構。接著，於內層介電層上形成一開口，使一部份的金屬銲墊暴露於外。再於內層介電層之上形成一個覆蓋隔離層，並延伸覆蓋開口的側壁以及金屬銲墊。然後，圖案化此一覆蓋隔離層，使一部份金屬銲墊暴露於外。It is still another object of the present invention to provide a method of fabricating a pad structure comprising the steps of first providing an interconnect structure having an inner dielectric layer and at least one metal pad. Next, an opening is formed in the inner dielectric layer to expose a portion of the metal pad to the outside. A cover spacer is formed over the inner dielectric layer and extends over the sidewalls of the opening and the metal pads. Then, the overlying isolation layer is patterned to expose a portion of the metal pads to the outside.

在本發明之一實施例中，形成內連線結構的步驟包括下述步驟：先提供一基材，再於基材上形成複數個圖案化金屬導線層，以及隔離這些圖案化金屬導線層的內層介電層。接著，於圖案化金屬導線層與內層介電層之上，形成一鈍化層。In an embodiment of the invention, the step of forming the interconnect structure comprises the steps of: first providing a substrate, forming a plurality of patterned metal wire layers on the substrate, and isolating the patterned metal wire layers. Inner dielectric layer. Next, a passivation layer is formed over the patterned metal wiring layer and the inner dielectric layer.

在本發明之一實施例中，在形成內連線結構之前，更包括於基材上形成至少一個電晶體元件及一部份的微電機構件。In an embodiment of the invention, at least one of the transistor elements and a portion of the micro-motor component are formed on the substrate prior to forming the interconnect structure.

在本發明之一實施例中，在形成鈍化層之前，更包括在金屬銲墊上形成一個金屬氧化層。In an embodiment of the invention, before forming the passivation layer, a metal oxide layer is further formed on the metal pad.

在本發明之一實施例中，形成覆蓋隔離層的材質，係選自於由介氧化鋁、氮化矽、非晶矽、氮碳化矽、有機聚合物或上述任意組合的一族群。In one embodiment of the present invention, the material forming the cover layer is selected from the group consisting of alumina, tantalum nitride, amorphous tantalum, niobium nitridide, organic polymer, or any combination thereof.

在本發明之一實施例中，更包括於覆蓋隔離層上形成一個硬罩幕層，並且使其不與金屬銲墊接觸。In an embodiment of the invention, a hard mask layer is formed on the cover spacer layer and is not in contact with the metal pad.

在本發明之一實施例中，在形成硬罩幕層之前，更包括：在覆蓋隔離層上形成一個二氧化矽層，並且使此二氧化矽層，未延伸超過此一開口。In an embodiment of the invention, before forming the hard mask layer, the method further comprises: forming a ruthenium dioxide layer on the cover spacer layer, and leaving the ruthenium dioxide layer not extending beyond the opening.

根據上述實施例，本發明係提出一種銲墊結構及其製造方法。先在一內連線結構中定義一開口，並將一部分的金屬銲墊暴露出來。再以一個覆蓋隔離層，來覆蓋銲墊開口的側壁及暴露出來的金屬銲墊。之後，再圖案化位於金屬銲墊上的覆蓋隔離層，使一部分的金屬銲墊再度由此一開口暴露出來。According to the above embodiment, the present invention provides a pad structure and a method of fabricating the same. An opening is defined in an interconnect structure and a portion of the metal pad is exposed. A cover layer is then covered to cover the sidewalls of the pad opening and the exposed metal pads. Thereafter, the overlying isolation layer on the metal pad is patterned to expose a portion of the metal pad to the opening again.

由於，覆蓋隔離層的材質相較於內連線結構的內層介電層，具有較佳的抗蝕刻能力。因此，當覆蓋隔離層完全覆蓋開口的側壁時，即可防止後續用來形成微電機構件開口的蝕刻製程，對內層介電層產生側蝕，降低銲墊結構受到後續製程應力破壞的機率。又由於，上述製程可以減少後續製程使用的光罩數量，相較於其他習知技術，具有簡化製程及降低成本的優勢，達到上述發明目的。Since the material covering the isolation layer has better etching resistance than the inner dielectric layer of the interconnect structure. Therefore, when the covering isolation layer completely covers the sidewall of the opening, the subsequent etching process for forming the opening of the micro-motor component can be prevented, the side etching of the inner dielectric layer can be caused, and the probability that the pad structure is damaged by the subsequent process stress can be reduced. Moreover, the above process can reduce the number of masks used in subsequent processes, and has the advantages of simplifying the process and reducing the cost compared with other conventional technologies, and achieving the above object.

為讓本發明之上述和其他目的、特徵和優點能更明顯易懂，下文特舉較佳實施例，並配合所附圖式，作詳細說明如下。The above and other objects, features and advantages of the present invention will become more <RTIgt;

本發明的目的就是在提供一種銲墊結構及其製造方法，不僅可解決習知銲墊結構易受後續製程應力破壞的問題，且製作程序具有成本優勢。為讓本發明之上述和其他目的、特徵和優點能更明顯易懂，下文特舉一種微電機構系統元件的結構與製作方法做較佳實施例，並配合所附圖式，作詳細說明如下。The object of the present invention is to provide a pad structure and a manufacturing method thereof, which not only solves the problem that the conventional pad structure is susceptible to stress damage in subsequent processes, but also has a cost advantage in the manufacturing process. In order to make the above and other objects, features and advantages of the present invention more apparent and obvious, the following is a preferred embodiment of the structure and fabrication method of the micro-electrical system component, and the detailed description is as follows .

請參照圖1A至圖1E，圖1A至圖1E係根據本發明的一較佳實施例，所繪示的一系列製作微電機構系統元件100的製程剖面圖。在本發明的一些實施例之中，微電機構系統元件100可以包含一個微電機構件104，例如微聲波感測器、微陀螺儀感測器、加速度感測器或時脈產生及震盪器。1A-1E, FIG. 1A to FIG. 1E are cross-sectional views showing a process of fabricating a micro-electric system component 100 according to a preferred embodiment of the present invention. In some embodiments of the invention, the micro-electrical system component 100 may include a micro-motor component 104, such as a microsonic sensor, a microgyroscope sensor, an acceleration sensor, or a clock generation and oscillator.

形成微電機構系統元件100的製程包含下述步驟：首先提供一基材101，並在基材101上形成包含有至少一個微電機構件104，以及用來處理、接收或傳輸微電機構件104所產生之電子訊號的電子元件(如圖1A所繪示)。例如，在本實施例之中，基材101為一種矽基材，較佳為一晶圓。而形成於基材101之上的電子元件，至少包括了一個互補式金屬-氧化物-半導體(Complementary Metal-Oxide-Semiconductor，CMOS)電晶體102。The process of forming the micro-electrical system component 100 includes the steps of first providing a substrate 101 and forming at least one micro-motor component 104 on the substrate 101, and for processing, receiving, or transmitting the micro-motor component 104. The electronic component of the generated electronic signal (as shown in Figure 1A). For example, in the present embodiment, the substrate 101 is a tantalum substrate, preferably a wafer. The electronic component formed on the substrate 101 includes at least one complementary metal-oxide-semiconductor (CMOS) transistor 102.

接著，在基材101與互補式金屬-氧化物-半導體電晶體102之上形成內連線結構103(如圖1B所繪示)。內連線結構103，包含複數個相互堆疊的圖案化金屬導線層，例如金屬導線層103a和103b；隔離金屬導線層103a和103b的內層介電層103c；以及導通金屬導線層103a和103b的接觸窗或介層窗103d。Next, an interconnect structure 103 (shown in FIG. 1B) is formed over the substrate 101 and the complementary metal-oxide-semiconductor transistor 102. The interconnect structure 103 includes a plurality of patterned metal wire layers stacked on each other, such as metal wire layers 103a and 103b; an inner dielectric layer 103c separating the metal wire layers 103a and 103b; and a conductive metal wire layer 103a and 103b. Contact window or via window 103d.

在本發明的一些實施例之中，金屬導線層103a和103b，較佳係由圖案化鋁金屬層所構成，用來電性連結微電機構件104與互補式金屬-氧化物-半導體電晶體102。其中，位於最上層的金屬導線層103a，有一部分係被提供作為銲墊(為了清楚說明起見，以下以金屬銲墊107表示)。金屬銲墊107可藉由錫球或打線與外部電子元件電性連結(未繪示)。In some embodiments of the present invention, the metal wiring layers 103a and 103b are preferably formed of a patterned aluminum metal layer for electrically connecting the micro-motor component 104 and the complementary metal-oxide-semiconductor transistor 102. Among them, a portion of the uppermost metal wiring layer 103a is provided as a bonding pad (for the sake of clarity, the following is indicated by a metal pad 107). The metal pad 107 can be electrically connected to an external electronic component (not shown) by solder balls or wire bonding.

之後，在內層介電層103c和金屬銲墊107覆蓋一鈍化層105。鈍化層105較佳係氮化矽層。接著，在進行一蝕刻製程，移除一部份的鈍化層105表面，以形成一開口106，並將一部分的金屬銲墊107暴露於外(如圖1C所繪示)。Thereafter, the inner dielectric layer 103c and the metal pad 107 cover a passivation layer 105. The passivation layer 105 is preferably a tantalum nitride layer. Next, an etching process is performed to remove a portion of the surface of the passivation layer 105 to form an opening 106 and expose a portion of the metal pad 107 (as shown in FIG. 1C).

但值得注意的是，在本發明的另外一些實施例之中(請參照圖1C’)，在尚未形成鈍化層105之前，較佳可以進行一沉積薄膜製程或熱製程(例如，熱氧化製程)，在金屬銲墊107上產生一層氧化鋁薄層。而一部分氧化鋁薄層，並在形成鈍化層105之後，由蝕刻製程所移除，並在金屬銲墊107與開口106的同側，但未暴露於外的表面上，形成一個圖案化的金屬氧化層112。It should be noted, however, that in other embodiments of the present invention (please refer to FIG. 1C'), a deposition film process or a thermal process (eg, a thermal oxidation process) may preferably be performed before the passivation layer 105 has been formed. A thin layer of aluminum oxide is formed on the metal pad 107. And a portion of the aluminum oxide layer, after forming the passivation layer 105, is removed by the etching process, and forms a patterned metal on the same side of the metal pad 107 and the opening 106, but not exposed to the outer surface. Oxide layer 112.

然後，在鈍化層105之上以及金屬銲墊107暴露於外的部分，形成一個覆蓋隔離層108，以及形成於覆蓋隔離層108上的硬罩幕層110。如圖1D所繪示，覆蓋隔離層108延伸進入開口106的部份，覆蓋了開口106的側壁106a；而且在開口106之側壁106a與金屬銲墊107鄰接的位置上，形成一個導角θ。Then, over the passivation layer 105 and the portion where the metal pad 107 is exposed, a cover spacer 108 is formed, and a hard mask layer 110 formed on the cover spacer 108 is formed. As shown in FIG. 1D, a portion of the cover spacer 108 extending into the opening 106 covers the sidewall 106a of the opening 106; and a leading angle θ is formed at a position where the sidewall 106a of the opening 106 abuts the metal pad 107.

在本發明的較佳實施例中，形成覆蓋隔離層108的材質，係選自於由氧化鋁、氮化矽、非晶矽、氮碳化矽、有機聚合物或上述任意組合所組成之一族群。且覆蓋隔離層108可以是沉積於，鈍化層105和部份金屬銲墊107上的氧化鋁層、氮化矽、非晶矽或氮碳化矽單一沉積層或多層堆疊；亦或者是藉由旋塗製程，塗佈有機聚合物於鈍化層105和部份金屬銲墊107上的有機聚合物層。硬罩幕層110較佳為鋁金屬層。In a preferred embodiment of the present invention, the material forming the cover spacer 108 is selected from the group consisting of alumina, tantalum nitride, amorphous germanium, niobium oxynitride, organic polymer or any combination thereof. . The cover isolation layer 108 may be an aluminum oxide layer deposited on the passivation layer 105 and a portion of the metal pad 107, a tantalum nitride, an amorphous germanium or a single deposited layer or a multi-layer stack of niobium carbide, or by spin The coating process coats the organic polymer layer on the passivation layer 105 and a portion of the metal pad 107. The hard mask layer 110 is preferably an aluminum metal layer.

接著，進行第二次蝕刻製程，移除在開口106中的一部份硬罩幕層110和覆蓋隔離層108，藉以再次地使一部分的金屬銲墊107經由開口106暴露出來。其中，圖案化後的硬罩幕層110，並不與金屬銲墊107接觸。Next, a second etching process is performed to remove a portion of the hard mask layer 110 and the capping isolation layer 108 in the opening 106, thereby again exposing a portion of the metal pad 107 through the opening 106. The patterned hard mask layer 110 is not in contact with the metal pad 107.

在第二次蝕刻製程之後，再進行至少一次蝕刻製程(例如，結構異向性蝕刻製程)在內層介電層103c中形成微電機構件開口113，將微電機構件104暴露出來，形成如圖1E所繪示的微電機構系統元件100。After the second etching process, at least one etching process (for example, a structural anisotropic etching process) is performed to form the micro-motor component opening 113 in the inner dielectric layer 103c, and the micro-motor component 104 is exposed to form a pattern. The micro-electrical system component 100 illustrated in 1E.

又在本發明的另一些實施例之中(延續圖1C’的實施例)，為了增加覆蓋隔離層108的絕緣性，較佳可以在覆蓋隔離層108和硬罩幕層110之間，形成一個二氧化矽層111。為了防止二氧化矽層111受到後續蝕刻製程的損傷，二氧化矽層111較佳必須包埋於和硬罩幕層110之中。二氧化矽層111的形成步驟包括：在尚未形成硬罩幕層110之前，先於覆蓋隔離層108上形成一個二氧化矽層111，再藉由圖案化步驟，使二氧化矽層111不會延伸超過開口106。接著，再於覆蓋隔離層108上形成硬罩幕層110，將圖案化後的二氧化矽層111完全覆蓋(如圖1D’所繪示)。在經過第二次蝕刻製程之後，圖案化的二氧化矽層111仍完全包覆於覆蓋隔離層108和硬罩幕層110之中。In still other embodiments of the present invention (continuing the embodiment of FIG. 1C'), in order to increase the insulation of the cover spacer 108, it is preferable to form a cover between the cover spacer 108 and the hard mask layer 110. The cerium oxide layer 111. In order to prevent the ruthenium dioxide layer 111 from being damaged by subsequent etching processes, the ruthenium dioxide layer 111 preferably has to be embedded in the hard mask layer 110. The step of forming the cerium oxide layer 111 includes: forming a cerium oxide layer 111 on the overlying isolation layer 108 before the hard mask layer 110 is formed, and then the cerium oxide layer 111 is not formed by the patterning step. Extending beyond the opening 106. Next, a hard mask layer 110 is formed on the cover spacer layer 108 to completely cover the patterned ceria layer 111 (as shown in FIG. 1D'). After the second etching process, the patterned ceria layer 111 is still completely encapsulated in the capping spacer layer 108 and the hard mask layer 110.

在第二次蝕刻製程之後，再進行至少一次蝕刻製程(例如結構異向性蝕刻製程)，在內層介電層103c中形成微電機構件開口113，將微電機構件104暴露出來，形成如圖1E’所繪示的微電機構系統元件100’。After the second etching process, at least one etching process (for example, a structural anisotropic etching process) is performed, and the micro-motor component opening 113 is formed in the inner dielectric layer 103c to expose the micro-motor component 104 to form a figure. The micro-electrical system component 100' depicted in 1E'.

在本實施例之中，微電機構系統元件100’包括基材101、電晶體元件(互補式金屬-氧化物-半導體電晶體102)、微電機構件104以及銲墊結構。其中，互補式金屬-氧化物-半導體電晶體102、微電機構件104和銲墊結構，都形成於基材101之上。而銲墊結構包括：內連線結構103(至少包含金屬銲墊107、內層介電層103c和鈍化層105)、圖案化的二氧化矽層111、金屬氧化層112、覆蓋隔離層108以及硬罩幕層110。In the present embodiment, the micro-electric system component 100' includes a substrate 101, a transistor element (complementary metal-oxide-semiconductor transistor 102), a micro-motor component 104, and a pad structure. The complementary metal-oxide-semiconductor transistor 102, the micro-motor component 104, and the pad structure are all formed on the substrate 101. The pad structure includes: an interconnect structure 103 (including at least a metal pad 107, an inner dielectric layer 103c and a passivation layer 105), a patterned ceria layer 111, a metal oxide layer 112, a capping layer 108, and Hard mask layer 110.

內連線結構103形成於基材101之上，具有一個開口106。金屬銲墊107位於內連線結構103之中，並與互補式金屬-氧化物-半導體電晶體102和微電機構件104電性連結。覆蓋隔離層108位於介電層之上，並延伸覆蓋開口106的側壁106a，而與金屬銲墊107接觸，使一部份金屬銲墊107由該開口106暴露於外。硬罩幕層110位於覆蓋隔離層108上，且不與金屬銲墊107接觸。圖案化的二氧化矽層111，包埋於覆蓋隔離層108與硬罩幕層110之間。金屬氧化層112a，形成於金屬銲墊107上，與開口106同側但未暴露於外的表面上。The interconnect structure 103 is formed over the substrate 101 and has an opening 106. The metal pad 107 is located in the interconnect structure 103 and is electrically coupled to the complementary metal-oxide-semiconductor transistor 102 and the micro-motor component 104. The cover spacer layer 108 is over the dielectric layer and extends over the sidewall 106a of the opening 106 to be in contact with the metal pad 107 such that a portion of the metal pad 107 is exposed from the opening 106. The hard mask layer 110 is on the cover spacer layer 108 and is not in contact with the metal pad 107. The patterned ceria layer 111 is embedded between the cover spacer layer 108 and the hard mask layer 110. A metal oxide layer 112a is formed on the metal pad 107 on the same side as the opening 106 but not exposed to the outer surface.

由於，相較於內層介電層103c的二氧化矽材質，覆蓋隔離層108所選用的材質，不僅提供與介電層103c相當的絕緣性。而且，硬罩幕層110和覆蓋隔離層108對於蝕刻劑(例如，氫氟酸(HF))的抵抗能力，也遠高過二氧化矽。因此，完全地包覆住開口106側壁106a的硬罩幕層110和覆蓋隔離層108，恰可防止用來形成微電機構件開口113的蝕刻製程，在開口106側壁106a造成側蝕的現象。由上述製程所形成的銲墊結構，將較不易再因為後續的製程應力而產生脫層現象發生。Since the material selected for covering the spacer layer 108 is compared with the material of the cap layer of the inner dielectric layer 103c, it provides insulation equivalent to that of the dielectric layer 103c. Moreover, the hard mask layer 110 and the overlying isolation layer 108 are also much more resistant to etchants (eg, hydrofluoric acid (HF)) than cerium oxide. Thus, the hard mask layer 110 and the overlying isolation layer 108 that completely encase the sidewalls 106a of the opening 106 prevent the etching process used to form the microelectromechanical component opening 113 from causing side erosion at the sidewall 106a of the opening 106. The pad structure formed by the above process will be less likely to cause delamination due to subsequent process stress.

再者，上述製程並不需要在開口106周邊定義額外的隔離結構，例如隔離圈(isolation ring)，不僅結構與製程簡單，且可以減少後續製程使用的光罩數量。因此上述實施例所提供的銲墊結構及其製程方法明顯具有成本優勢。Moreover, the above process does not need to define an additional isolation structure around the opening 106, such as an isolation ring, which is not only simple in structure and process, but also reduces the number of masks used in subsequent processes. Therefore, the pad structure and the manufacturing method thereof provided by the above embodiments have obvious cost advantages.

根據上述實施例，本發明係提出一種銲墊結構及其製造方法。其中此一銲墊結構，係藉由兩次蝕刻製程來完成。先在一內連線結構中定義一開口，並將一部分的金屬銲墊暴露出來。再以一個覆蓋隔離層，來覆蓋銲墊開口的側壁及暴露出來的金屬銲墊。之後，再圖案化位於金屬銲墊上的覆蓋隔離層，使一部分的金屬銲墊再度由此一開口暴露出來。According to the above embodiment, the present invention provides a pad structure and a method of fabricating the same. The pad structure is completed by two etching processes. An opening is defined in an interconnect structure and a portion of the metal pad is exposed. A cover layer is then covered to cover the sidewalls of the pad opening and the exposed metal pads. Thereafter, the overlying isolation layer on the metal pad is patterned to expose a portion of the metal pad to the opening again.

由於，覆蓋隔離層的材質相較於內連線結構的內層介電層，具有較佳的抗蝕刻能力，可防止後續的蝕刻製程對內層介電層產生側蝕，解決習知的銲墊結構易受後續製程的應力破壞的問題。又由於，上述製程可以減少後續製程所使用的光罩數量，相較於其他習知技術，具有簡化製程及降低成本的優勢，達到上述發明目的。Since the material of the covering spacer layer has better etching resistance than the inner dielectric layer of the interconnect structure, the subsequent etching process can prevent side etching of the inner dielectric layer, and the conventional soldering is solved. The pad structure is susceptible to stress damage in subsequent processes. Moreover, the above process can reduce the number of masks used in subsequent processes, and has the advantages of simplifying the process and reducing the cost compared with other conventional technologies, and achieving the above object.

雖然本發明已以較佳實施例揭露如上，然其並非用以限定本發明，任何熟習此技藝者，在不脫離本發明之精神和範圍內，當可作些許之更動與潤飾，因此本發明之保護範圍當視後附之申請專利範圍所界定者為準。While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

100．．．微電機構系統元件100. . . Micro-electrical system component

100’．．．微電機構系統元件100’. . . Micro-electrical system component

101．．．基材101. . . Substrate

102．．．互補式金屬-氧化物-半導體電晶體102. . . Complementary metal-oxide-semiconductor transistor

103．．．內連線結構103. . . Inline structure

103a．．．金屬導線層103a. . . Metal wire layer

103b．．．金屬導線層103b. . . Metal wire layer

103c．．．內層介電層103c. . . Inner dielectric layer

103d．．．接觸窗103d. . . Contact window

104．．．微電機構件104. . . Micro motor component

105．．．鈍化層105. . . Passivation layer

106．．．開口106. . . Opening

106a．．．開口之側壁106a. . . Side wall of the opening

107．．．金屬銲墊107. . . Metal pad

108．．．覆蓋隔離層108. . . Covering the isolation layer

110．．．硬罩幕層110. . . Hard mask layer

111．．．二氧化矽層111. . . Ceria layer

112．．．金屬氧化層112. . . Metal oxide layer

113．．．微電機構件開口113. . . Micro motor component opening

θ．．．導角θ. . . Leading angle

圖1A至圖1E係根據本發明的一較佳實施例，所繪示的一系列製作微電機構系統元件的製程剖面圖。1A-1E are cross-sectional views showing a series of processes for fabricating micro-electric system components in accordance with a preferred embodiment of the present invention.

圖1C’至圖1E’係根據本發明的另一較佳實施例，所繪示的一部分製作微電機構系統元件的製程剖面圖。1C' to 1E' are cross-sectional views showing a portion of a process for fabricating a micro-electric system component in accordance with another preferred embodiment of the present invention.

101．．．基材101. . . Substrate

103．．．內連線結構103. . . Inline structure

103a．．．金屬導線層103a. . . Metal wire layer

103b．．．金屬導線層103b. . . Metal wire layer

103c．．．內層介電層103c. . . Inner dielectric layer

103d．．．接觸窗103d. . . Contact window

104．．．微電機構件104. . . Micro motor component

105．．．鈍化層105. . . Passivation layer

106．．．開口106. . . Opening

106a．．．開口之側壁106a. . . Side wall of the opening

107．．．金屬銲墊107. . . Metal pad

108．．．覆蓋隔離層108. . . Covering the isolation layer

110．．．硬罩幕層110. . . Hard mask layer

111．．．二氧化矽層111. . . Ceria layer

112．．．金屬氧化層112. . . Metal oxide layer

113．．．微電機構件開口113. . . Micro motor component opening

θ．．．導角θ. . . Leading angle

Claims

一種銲墊結構，包括：一內連線結構，具有至少一開口和至少一金屬銲墊；以及一覆蓋隔離層，位於該內連線結構之上，並延伸覆蓋該開口的側壁，而與該金屬銲墊接觸，使一部份該金屬銲墊由該開口暴露於外。A pad structure comprising: an interconnect structure having at least one opening and at least one metal pad; and a cover isolation layer over the interconnect structure and extending over the sidewall of the opening The metal pads are in contact such that a portion of the metal pads are exposed from the opening.

如申請專利範圍第1項所述之該銲墊結構，其中構成該覆蓋隔離層的材質，係選自於由氧化鋁(Al₂O₃)、氮化矽(SiN)、非晶矽(amorphous silicon)、氮碳化矽(SiCN)、有機聚合物或上述任意組合所組成之一族群。The pad structure according to claim 1, wherein the material constituting the cover layer is selected from the group consisting of alumina (Al ₂ O ₃ ), tantalum nitride (SiN), and amorphous germanium (amorphous). A group of silicon, silicon lanthanum carbide (SiCN), organic polymer or any combination of the above.

如申請專利範圍第1項所述之該銲墊結構，其中該內連線結構包括：一內層介電層，用來承載該金屬銲墊；以及一鈍化層(passivation layer)，覆蓋於該內層介電層上，而該開口則係穿透該鈍化層，將一部份該金屬銲墊暴露於外。The solder pad structure of claim 1, wherein the interconnect structure comprises: an inner dielectric layer for carrying the metal pad; and a passivation layer covering the The inner dielectric layer is formed through the passivation layer to expose a portion of the metal pad to the outside.

如申請專利範圍第1項所述之該銲墊結構，更包括一硬罩幕層位於該覆蓋隔離層上，且不與該金屬銲墊接觸。The pad structure according to claim 1, further comprising a hard mask layer on the cover isolation layer and not in contact with the metal pad.

如申請專利範圍第4項所述之該銲墊結構，其中該硬罩幕層係一鋁金屬層。The pad structure of claim 4, wherein the hard mask layer is an aluminum metal layer.

如申請專利範圍第1項所述之該銲墊結構，更包括一二氧化矽層，包埋於該覆蓋隔離層與該硬罩幕層之間。The solder pad structure of claim 1, further comprising a layer of germanium dioxide embedded between the cover spacer layer and the hard mask layer.

如申請專利範圍第1項所述之該銲墊結構，更包括一金屬氧化層，形成於該金屬銲墊與該開口同側，但未暴露於外的一表面上。The pad structure according to claim 1, further comprising a metal oxide layer formed on the same side of the metal pad but not exposed to the outer surface.

如申請專利範圍第1項所述之該銲墊結構，其中該覆蓋隔離層具有一導角，形成於該開口的側壁與該金屬銲墊鄰接的一位置上。The pad structure of claim 1, wherein the cover spacer has a lead angle formed at a position adjacent to the metal pad of the sidewall of the opening.

一種微電機構系統元件(Micro-Electro-Mechanical System，MEMS)，包括：一基材；一電晶體元件，形成於該基材之上；一微電機構件，形成於該基材之上；以及一銲墊結構，包括：一內連線結構，形成於該基材之上，具有一開口和至少一金屬銲墊，位於該內連線結構之中，並與該電晶體元件和該微電機構件電性連結；以及一覆蓋隔離層，位於該內連線結構之上，並延伸覆蓋該開口的側壁，而與該金屬銲墊接觸，且使一部份該金屬銲墊由該開口暴露於外。A Micro-Electro-Mechanical System (MEMS) comprising: a substrate; a transistor element formed on the substrate; a micro-motor component formed on the substrate; a pad structure comprising: an interconnect structure formed on the substrate, having an opening and at least one metal pad disposed in the interconnect structure and the transistor component and the micromotor Electrically connecting the component; and a cover isolation layer over the interconnect structure and extending over the sidewall of the opening to contact the metal pad and exposing a portion of the metal pad to the opening outer.

如申請專利範圍第9項所述之該微電機構系統元件，更包括一硬罩幕層位於該覆蓋隔離層上，且不與該金屬銲墊接觸。The micro-electric system component of claim 9, further comprising a hard mask layer on the cover isolation layer and not in contact with the metal pad.

如申請專利範圍第9項所述之該微電機構系統元件，其中該覆蓋隔離層具有一導角，形成於該開口的側壁與該金屬銲墊鄰接的一位置上。The micro-electric system component of claim 9, wherein the covering spacer has a lead angle formed at a position adjacent to a sidewall of the opening.

如申請專利範圍第9項所述之該微電機構系統元件，更包括一二氧化矽層，包埋於該覆蓋隔離層與該硬罩幕層之間。The micro-electrical system component as described in claim 9 further comprising a ruthenium dioxide layer embedded between the overlying isolation layer and the hard mask layer.

如申請專利範圍第9項所述之該微電機構系統元件，更包括一金屬氧化層，形成於該金屬銲墊與該開口同側，但未暴露於外的一表面上。The micro-electric system component as described in claim 9 further comprising a metal oxide layer formed on the same side of the metal pad but not exposed to the outer surface.

一種銲墊結構的製造方法，包括：提供一內連線結構，包含至少一金屬銲墊及一內層介電層；於該內層介電層上形成一開口，使一部份該金屬銲墊暴露於外；於該內層介電層之上形成一覆蓋隔離層，並延伸覆蓋該開口的側壁以及該金屬銲墊；以及圖案化該覆蓋隔離層，使一部份該金屬銲墊暴露於外。A method for fabricating a pad structure includes: providing an interconnect structure comprising at least one metal pad and an inner dielectric layer; forming an opening in the inner dielectric layer to enable a portion of the metal bond The pad is exposed to the outside; a cover spacer is formed on the inner dielectric layer, and the sidewall covering the opening and the metal pad are extended; and the cover spacer is patterned to expose a portion of the metal pad Outside.

如申請專利範圍第14項所述之該銲墊結構的製造方法，其中形成該內連線結構的步驟包括：提供一基材；於該基材上形成複數個圖案化金屬導線層以及隔離該些圖案化金屬導線層的該內層介電層；以及於該些圖案化金屬導線層與該內層介電層之上，形成一鈍化層。The method of manufacturing the pad structure of claim 14, wherein the step of forming the interconnect structure comprises: providing a substrate; forming a plurality of patterned metal wire layers on the substrate; and isolating the substrate The inner dielectric layer of the patterned metal wiring layer; and a passivation layer formed on the patterned metal wiring layer and the inner dielectric layer.

如申請專利範圍第15項所述之該銲墊結構的製造方法，其中在形成該金屬導線層之前，更包括於該基材上形成至少一電晶體元件及部分的一微電機構件。The method of manufacturing the pad structure of claim 15, wherein before forming the metal wire layer, further comprising forming at least one transistor component and a portion of the micro-motor component on the substrate.

如申請專利範圍第15項所述之該銲墊結構的製造方法，其中形成該鈍化層之前，更包括在該金屬銲墊上形成一金屬氧化層。The method for manufacturing the pad structure according to claim 15, wherein before forming the passivation layer, further comprising forming a metal oxide layer on the metal pad.

如申請專利範圍第14項所述之該銲墊結構的製造方法，其中形成該覆蓋隔離層的材質，係選自於由介氧化鋁、氮化矽、非晶矽、氮碳化矽、有機聚合物或上述任意組合的一族群。The method for manufacturing the pad structure according to claim 14, wherein the material for forming the covering spacer layer is selected from the group consisting of alumina, tantalum nitride, amorphous germanium, niobium nitriding, and organic polymer. Or a group of any combination of the above.

如申請專利範圍第14項所述之該銲墊結構的製造方法，更包括：於該覆蓋隔離層上形成一硬罩幕層，且使其不與該金屬銲墊接觸。The method for manufacturing the pad structure of claim 14, further comprising: forming a hard mask layer on the cover spacer layer and not contacting the metal pad.

如申請專利範圍第19項所述之該銲墊結構的製造方法，其中在形成該硬罩幕層之前，更包括在該覆蓋隔離層上，形成一二氧化矽層，並且使該二氧化矽層，未延伸超過該開口。The method of manufacturing the pad structure of claim 19, wherein before forming the hard mask layer, further comprising forming a ceria layer on the cover spacer layer, and forming the ceria layer The layer does not extend beyond the opening.