METHOD OF BONDING SEMICONDUCTOR SUBSTRATE AND MEMS DEVICE

• US 20120299128A1
• Filed: 12/11/2009
• Published: 11/29/2012
• Est. Priority Date: 12/11/2009
• Status: Abandoned Application

• Current Assignee: Pioneer Corporation, Pioneer Micro Technology Corporation (Pioneer Corporation)
• Original Assignee: Pioneer Corporation, Pioneer Micro Technology Corporation (Pioneer Corporation)
• Inventors: Noda, Naoki, Yokouchi, Toshio, Ishimori, Masahiro
• Application Number:
  US13/513,403
• Publication Number:
  US 20120299128A1
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B23K 20/023 Thermo-compression bonding
• CPC Class Codes: B23K 20/16 with interposition of special material to facilitate connection of the parts, e.g. material for absorbing or producing gas
• CPC Class Codes: B23K 20/233 without ferrous layer
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B81C 1/00269 Bonding of solid lids or wafers to the substrate
• CPC Class Codes: B81C 2203/0118 Bonding a wafer on the substrate, i.e. where the cap consists of another wafer
• CPC Class Codes: H01L 2224/29117 the principal constituent melting at a temperature of greater than or equal to 400°C and less than 950°C
• CPC Class Codes: H01L 2224/29124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/45032 Two-layer arrangements
• CPC Class Codes: H01L 2224/83203 Thermocompression bonding, e.g. diffusion bonding, pressure joining, thermocompression welding or solid-state welding
• CPC Class Codes: H01L 2224/838 Bonding techniques
• CPC Class Codes: H01L 2224/83805 involving forming a eutectic alloy at the bonding interface
• CPC Class Codes: H01L 24/29 of an individual layer connector
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 24/83 using a layer connector
• CPC Class Codes: H01L 24/94 at wafer-level, i.e. with connecting carried out on a wafer comprising a plurality of undiced individual devices
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01032 : Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/1461 : MEMS
• CPC Class Codes: H01L 2924/16235 : Connecting to a semiconductor or solid-state bodies, i.e. cap-to-chip

Abstract

A method of bonding a semiconductor substrate in which a first semiconductor substrate is bonded with a second semiconductor substrate by eutectic bonding with pressurization and heating, an aluminum containing layer primarily made of aluminum and a germanium layer in a polymer state being interposed between a bonding surface of the first semiconductor substrate and a bonding surface of the second semiconductor substrate, the method including a step of: setting a weight ratio of the germanium layer to an aluminum containing layer to be eutectic alloyed is between 27 wt % to 52 wt %.

Claims

1. A method of bonding a semiconductor substrate in which a first semiconductor substrate is bonded with a second semiconductor substrate by eutectic bonding with pressurization and heating, an aluminum containing layer primarily made of aluminum and a germanium layer in a contact state being interposed between a bonding surface of the first semiconductor substrate and a bonding surface of the second semiconductor substrate, the method comprising steps of:

setting a weight ratio of the germanium layer to an aluminum containing layer to be eutectic alloyed is between 27 wt % to 52 wt %; and

adjusting film thickness of the germanium layer such that the whole germanium layer and a portion contacting the germanium layer of the aluminum containing layer are eutectic alloyed.

2. The method of bonding a semiconductor substrate according to claim 1, wherein the weight ratio is between 33 wt % to 42 wt %.

4. The method of bonding a semiconductor substrate according to claim 1, wherein the aluminum containing layer and the germanium layer are film-formed either on the first semiconductor substrate or on the second semiconductor substrate.

5. The method of bonding a semiconductor substrate according to claim 4, wherein the aluminum containing layer is film-formed in a ring shape in planar view as having predetermined width, and the germanium layer has one or more strip layer sections film-formed in a ring shape in planar view on the aluminum containing layer.

6. The method of bonding a semiconductor substrate according to claim 4, wherein the aluminum containing layer is film-formed in a ring shape in planar view as having predetermined width, and the germanium layer has a strip layer section film-formed in a ring shape in planar view and a plurality of branch layer sections branched from the strip layer section on the aluminum containing layer.

7. A MEMS device bonded by the method of bonding a semiconductor substrate according to claim 4, wherein the aluminum containing layer and the germanium layer are film-formed on the second semiconductor substrate and a pit is formed in the bonding surface of the first semiconductor substrate, in which a eutectic alloy generated by the pressurization and heating fills.

8. A MEMS device according bonded by the bonding method for a semi-conductor substrate in claim 7, wherein the first semiconductor substrate has a MEMS structure formed to be engraved at the bonding surface side thereof, and the second semiconductor substrate has an integrated circuit formed at the bonding surface side to control the MEMS structure.

9. The MEMS device according to claim 8, wherein the MEMS device is either one of an acceleration sensor, an angular velocity sensor, an infrared ray sensor, a pressure sensor, a magnetic sensor and a sonic sensor.

3. (canceled)