# US 7,071,077 B2 · Method for preparing a bonding surface of a semiconductor layer of a wafer

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,071,077 B2
- Document ID: US7071077B2
- Status: Granted
- Kind: B2
- Application number: 10/808,288
- Filed: 2004-03-25
- Published: 2004-10-21
- Granted: 2006-07-04
- Earliest claimed: 2003-03-26
- Assignees: S.O.I.Tec Silicon on Insulator Technologies
- Inventors: Christophe Maleville; Corinne Maunand Tussot
- Web page: https://patentgrep.com/patent/US7071077B2

## CPC

- H10P 70/15: {by wet cleaning only (H10P70/52 takes precedence)}
- B08B 3/12: by sonic or ultrasonic vibrations
- B08B 2203/005: the liquid being ozonated
- Y10S 438/974: Substrate surface preparation
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- B08B: CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A method for preparing a bonding surface of a semiconductor layer of a wafer is described. The method includes treating the bonding surface to oxidize contaminants, and then cleaning the bonding surface to remove essentially all remaining contaminants. Ozone is then used to oxidize the bonding surface to improve the hydrophilic properties of the bonding surface. In an implementation, two wafers are prepared and then bonded together to form a structure.

## Claims

### Claim 1

A method for preparing a bonding surface of a semiconductor layer of a wafer comprising:
treating the bonding surface to oxidize contaminants;
cleaning the bonding surface to remove essentially all remaining contaminants; and then
oxidizing the bonding surface with ozone to improve the hydrophilic properties of the bonding surface.

### Claim 2 (depends on 1)

The method of claim 1 wherein the cleaning of the bonding surface comprises treating the bonding surface with a first solution capable of removing isolated and encrusted particles, and then treating the bonding surface with a second solution capable of removing metallic contamination.

### Claim 3 (depends on 2)

The method of claim 2 wherein the first solution is a SC 1 solution that includes ammonium hydroxide (NH4OH), hydrogen peroxide (H2O2) and deionized water.

### Claim 4 (depends on 2)

The method of claim 2 wherein the second solution is a SC2 solution that includes hydrochloric acid (HCl), hydrogen peroxide (H2O2) and deionized water.

### Claim 5 (depends on 1)

The method of claim 1 wherein the cleaning step includes applying ultrasonic energy to assist in removing particulate contamination from the bonding surface.

### Claim 6 (depends on 1)

The method of claim 1 wherein the oxidizing comprises at least one of immersing the bonding surface in an ozone bath, or spraying ozone droplets onto the bonding surface, or exposing the bonding surface to an ozone gas.

### Claim 7 (depends on 1)

The method of claim 1 which further comprises preparing a bonding surface of a second wafer by treating the bonding surface to oxidize contaminants, cleaning the bonding surface to remove essentially all remaining contaminants, and oxidizing the bonding surface with ozone to improve the hydrophilic properties of the bonding surface, followed by contacting the bonding surface of the first wafer to the bonding surface of the second wafer to effect bonding therebetween and form a structure.

### Claim 8 (depends on 7)

The method of claim 7 wherein the bonding is at least partly achieved by hydrophilic adhesion of the bonding surfaces of the first and second wafers.

### Claim 9 (depends on 7)

The method of claim 7 further comprises applying a heat treatment to the structure to strengthen the bond between the first and second wafers.

### Claim 10 (depends on 7)

The method of claim 7 wherein the bonding surface of the second wafer exists on an oxide layer.

### Claim 11 (depends on 10)

The method of claim 10 wherein the semiconductor structure is a semiconductor on insulator (SOI) structure.

### Claim 12 (depends on 10)

The method of claim 10 wherein the oxide layer is an insulating layer.

### Claim 13 (depends on 7)

The method of claim 7 wherein the bonding surfaces of each of the first and second wafers exist on an oxide layer.

### Claim 14 (depends on 13)

The method of claim 13, wherein each oxide layer is an insulating layer.

### Claim 15 (depends on 7)

The method of claim 7, wherein at least one of the first or second wafers includes a zone of weakness to facilitate detachment of the structure.

### Claim 16 (depends on 7)

The method or claim 7, wherein the semiconductor wafer comprises silicon, germanium, SiGe, AlGaAs, GaAS, InGaAs, AlGaAsP, InGaAsP, InP, or another Group III–Group V semiconductor or Group II–Group VI semiconductor.

### Claim 17 (depends on 1)

The method of claim 1, wherein the first wafer includes a zone of weakness to facilitate detachment of a layer that includes the bonding surface.

### Claim 18

In a method for preparing a bonding surface of a semiconductor layer of a wafer for bonding to a second wafer wherein the bonding surface is cleaned to remove contaminants, the improvement which comprises oxidizing the bonding surface with ozone after the surface is cleaned to improve the hydrophilic properties of the bonding surface.