In wafer-to-wafer bonding technology, various methods have been developed to bond two package components (such as wafers) together. The available bonding methods include fusion bonding, eutectic bonding, direct metal bonding, hybrid bonding, and the like. In the fusion bonding, an oxide surface of a wafer is bonded to an oxide surface or a silicon surface of another wafer. In the eutectic bonding, two eutectic materials are placed together, and are applied with a high pressure and a high temperature. The eutectic materials are hence melted. When the melted eutectic materials are solidified, the wafers are bonded together. In the direct metal-to-metal bonding, two metal pads are pressed against each other at an elevated temperature, and the inter-diffusion of the metal pads causes the bonding of the metal pads. In the hybrid bonding, the metal pads of two wafers are bonded to each other through direct metal-to-metal bonding, and an oxide surface of one of the two wafers is bonded to an oxide surface or a silicon surface of the other wafer.
For a more complete understanding of the embodiments, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
The making and using of the embodiments of the disclosure are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are illustrative, and do not limit the scope of the disclosure.
A method for bonding package components and the apparatus for performing the bonding are provided in accordance with various exemplary embodiments. The intermediate stages of the bonding process are illustrated. The variations of the apparatus and bonding methods in accordance with embodiments are discussed. Throughout the various views and illustrative embodiments, like reference numbers are used to designate like elements.
Referring to
A pre-bonding is then performed to bond the package components together. The pre-bonding is performed in pre-bonding station 308. After the pre-bonding, the package components are bonded to each other. The bonded package components may then be unloaded from integrated hybrid bonding system 300 through unloading station 310, and transferred into annealing station 312. The bonding strength is then enhanced through a thermal annealing, which is held in thermal annealing station 312.
In the integrated hybrid bonding system 300, a plurality of transferring tools 314 are used to transfer the package components between stations 304, 306, and 308, so that stations 304, 306, and 308 may be integrated together as an integrated system. Transferring tools 314 may include robot arms (not shown), transferring guides (not shown), and/or the like, which are used to automatically transfer the package components from one station to another, so that the bonding process may be automated. After the bonding process is finished, the bonded package components are unloaded from integrated hybrid bonding system 300 using unloading station 310, which may include robot arms, for example. In addition, some or all of stations 304, 306, and 308 and transferring tools 314 may be connected to a central control unit 316, which controls, and coordinates, the operations of stations 304, 306, and 308 and transferring tools 314.
A brief hybrid bonding process is discussed herein referring to
In alternative embodiments, package component 100 is an interposer wafer, which is free from active devices therein. Package component 100 may, or may not, include passive devices (not shown) such as resistors, capacitors, inductors, transformers, and the like in accordance with some embodiments.
In yet alternative embodiments, package component 100 is a package substrate strip. In some embodiments, package component 100 includes laminate package substrates, wherein conductive traces 106 (which are schematically illustrated) are embedded in laminate dielectric layers 108. In alternative embodiments, package components 100 are build-up package substrates, which comprise cores (not shown) and conductive traces (represented by 106) built on opposite sides of the cores.
In each of the embodiments wherein package component 100 is a device wafer, an interposer wafer, a package substrate strip, or the like, surface dielectric layer 110 is formed at the surface of package component 100. In some embodiments, surface dielectric layer 110 is an oxide layer, which may comprise silicon oxide, SiON, SiN, or the like. Metal pads 112 are formed in surface dielectric layer 110, and may be electrically coupled to active devices 104 through metal lines and vias 106. Metal pads 112 may also be formed of copper, aluminum, nickel, tungsten, or alloys thereof. The top surface of surface dielectric layer 110 and the top surfaces of metal pads 112 are substantially level with each other.
In the embodiments wherein package component 100 is a device wafer, surface dielectric layer 110 and metal pads 112, which are used for the subsequent bonding, may be on the front side (the side with active devices 104) or the back side of substrate 102, although
Next, referring to
The plasma treatment may be performed in a vacuum environment (a vacuum chamber), for example, which is a part of the surface treatment station 304 (
Next, referring to
Integrated cleaning station 306 also includes a plurality of storages, for example, 424, 426, and 428. The plurality of storages is used to store the chemicals/solutions that are used in the metal oxide removal and the DI water cleaning. For example, 424, 426, and 428 may store an acidic solution, an alkaline solution, and DI water, respectively. Integrated cleaning station 306 is configured to mix the chemicals and the DI water, and dispose the chemicals, either mixed or not mixed, to nozzle 430, which is used to dispense the chemical solution to the package component (such as package component 100 in
Retractable wafer support 432 is located in chamber 402. Retractable wafer support 432 may extend or retract as desired to different levels during the integrated cleaning process. Hence, retractable wafer support 432 may raise package component 100, as shown in
Integrated cleaning station 306 also includes ultrasonic generator 436, which is used to generate ultrasound. The ultrasound is used in the cleaning process, for example, when DI water is disposed on package component 100. As also shown in
Referring to
In accordance with some embodiments, one or both of the alkaline cleaning and/or acid cleaning is performed on package component 100 before it is pre-bonded. After the alkaline cleaning and/or the acid cleaning, a DI water cleaning is performed, as shown in
During the alkaline cleaning, the acid cleaning, and possibly the DI water cleaning, air, clean air, nitrogen, or other type of gas, which are represented by arrows 440, may be blown out of outlets 434 (
Package component 200 is also cleaned using essentially the same process as shown in
Next, as shown in
After the pre-bonding, surface dielectric layer 110 and 210 are bonded to each other. The bonding strength, however, needs to be improved in a subsequent annealing step. The bonded package components 100 and 200 in combination are referred to as bonded pair 324 hereinafter. Bonded pair 324 is unloaded out of pre-bonding station 308 and integrated cleaning station 306 (
Referring to
In the embodiments of the present disclosure, by integrating the integrated cleaning station into the hybrid bonding system, the oxides on the surfaces of metal bonds are removed. Experiments have shown that in conventional bonding processes in which the DI water clean is performed, and no oxide removal is performed in the respective hybrid bonding station 300, a resulting bond structure has a clearly visible interface, indicating the inferior inter-diffusion of copper atoms. The bond quality is hence low. As a comparison, by removing the oxide in hybrid bonding system, there is substantially no metal oxide re-grown when the bonding is performed. The resulting bond structure has no visible interface, indicating the high-quality inter-diffusion of copper atoms has occurred, and quality of bonds is improved.
In accordance with some embodiments, a method includes performing a plasma activation on a surface of a first package component, removing oxide regions from surfaces of metal pads of the first package component, and performing a pre-bonding to bond the first package component to a second package component.
In accordance with other embodiments, a hybrid bonding system includes a plasma treatment chamber configured to perform a plasma cleaning on a package component, and an integrated cleaning station. The integrated cleaning station includes a chamber, and a plurality of storages outside of the chamber. The plurality of storages comprises a first storage storing one of an acidic solution and an alkaline solution therein and a second storage storing deionized water therein. The integrated cleaning station further includes a nozzle in the chamber and connected to the plurality of storages, and a retractable wafer support configured to hold the package component thereon. The hybrid bonding system further includes an alignment and pre-bonding station configure to align and bonding the package component with an additional package component.
Although the embodiments and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, and composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. In addition, each claim constitutes a separate embodiment, and the combination of various claims and embodiments are within the scope of the disclosure.
This application is a divisional of U.S. patent application Ser. No. 16/569,019, entitled “Integrate Rinse Module in Hybrid Bonding Platform,” filed on Sep. 12, 2019, which is a divisional of U.S. patent application Ser. No. 15/269,346, entitled “Integrate Rinse Module in Hybrid Bonding Platform,” filed on Sep. 19, 2016, now U.S. Pat. No. 10,665,449 issued May 26, 2020, which is a continuation of U.S. patent application Ser. No. 13/888,921, entitled “Integrate Rinse Module in Hybrid Bonding Platform,” filed on May 7, 2013, now U.S. Pat. No. 9,446,467 issued Sep. 20, 2016, which application claims the benefit of the following provisionally filed U.S. patent application: U.S. Patent Application No. 61/785,993, filed on Mar. 14, 2013, and entitled “Integrated Clean Station in Hybrid Bonding System,” which applications are hereby incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
4822639 | Fujii | Apr 1989 | A |
5672205 | Fujimoto | Sep 1997 | A |
5985739 | Plettner et al. | Nov 1999 | A |
6752872 | Inada | Jun 2004 | B2 |
6835523 | Yamazaki et al. | Dec 2004 | B1 |
7385283 | Wu | Jun 2008 | B2 |
7815739 | Matsuura | Oct 2010 | B2 |
7926439 | Sanada | Apr 2011 | B2 |
8286576 | Tamada | Oct 2012 | B2 |
9446467 | Huang et al. | Sep 2016 | B2 |
9773687 | Wakiyama | Sep 2017 | B2 |
10046372 | Goda | Aug 2018 | B2 |
20020036066 | Ogawa | Mar 2002 | A1 |
20030025962 | Nishimura | Feb 2003 | A1 |
20040106272 | Kwak | Jun 2004 | A1 |
20050014375 | Kim et al. | Jan 2005 | A1 |
20060130750 | Ishikawa | Jun 2006 | A1 |
20060141740 | Jeong | Jun 2006 | A1 |
20060185592 | Matsuura | Aug 2006 | A1 |
20070062646 | Ogawa et al. | Mar 2007 | A1 |
20070212884 | Yamamoto | Sep 2007 | A1 |
20070232023 | Tong et al. | Oct 2007 | A1 |
20080022928 | Sanada | Jan 2008 | A1 |
20080163889 | Predoaica et al. | Jul 2008 | A1 |
20080163899 | Takiguchi | Jul 2008 | A1 |
20090092162 | Huff et al. | Apr 2009 | A1 |
20100025863 | Gruber et al. | Feb 2010 | A1 |
20100040779 | Nagamine | Feb 2010 | A1 |
20100261332 | Kim et al. | Oct 2010 | A1 |
20110000512 | Toshima | Jan 2011 | A1 |
20120234356 | Nishi | Sep 2012 | A1 |
20130032179 | Kaneko | Feb 2013 | A1 |
20130072002 | Toyoda et al. | Mar 2013 | A1 |
20130320556 | Liu et al. | Dec 2013 | A1 |
20140263586 | Huang | Sep 2014 | A1 |
Number | Date | Country |
---|---|---|
2007538397 | Dec 2007 | JP |
1020050101324 | Oct 2005 | KR |
200739671 | Oct 2007 | TW |
I335066 | Jan 2008 | TW |
201003809 | Jan 2010 | TW |
Number | Date | Country | |
---|---|---|---|
20220216052 A1 | Jul 2022 | US |
Number | Date | Country | |
---|---|---|---|
61785993 | Mar 2013 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 16569019 | Sep 2019 | US |
Child | 17655638 | US | |
Parent | 15269346 | Sep 2016 | US |
Child | 16569019 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 13888921 | May 2013 | US |
Child | 15269346 | US |