METHOD OF PRODUCING EPITAXIAL SILICON WAFER, EPITAXIAL SILICON WAFER, AND METHOD OF PRODUCING SOLID-STATE IMAGE SENSING DEVICE

• US 20140134779A1
• Filed: 11/12/2013
• Published: 05/15/2014
• Est. Priority Date: 11/13/2012
• Status: Active Grant

• Current Assignee: Sumco Corporation
• Original Assignee: Sumco Corporation
• Inventors: Kadono, Takeshi
• Granted Patent: US 9,224,601 B2
• Time in Patent Office: Days
• US Class Current: 438/73
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 21/26566 of a cluster, e.g. using a gas cluster ion beam
• CPC Class Codes: H01L 21/3221 of silicon bodies, e.g. for gettering
• CPC Class Codes: H01L 21/3225 Thermally inducing defects using oxygen present in the silicon body for intrinsic gettering H01L21/3226 takes precedence
• CPC Class Codes: H01L 27/14687 Wafer level processing

Abstract

Provided is an epitaxial silicon wafer free of epitaxial defects caused by dislocation clusters and COPs with reduced metal contamination achieved by higher gettering capability and a method of producing the epitaxial wafer.

A method of producing an epitaxial silicon wafer includes a first step of irradiating a silicon wafer free of dislocation clusters and COPs with cluster ions to form a modifying layer formed from a constituent element of the cluster ions in a surface portion of the silicon wafer; and a second step of forming an epitaxial layer on the modifying layer of the silicon wafer.

Claims

1. A method of producing an epitaxial silicon wafer, comprising:

a first step of irradiating a silicon wafer free of dislocation clusters and COPs with cluster ions to form a modifying layer formed from a constituent element of the cluster ions in a surface portion of the silicon wafer; and

a second step of forming an epitaxial layer on the modifying layer of the silicon wafer.

2. The method of producing an epitaxial silicon wafer, according to claim 1, wherein the cluster ions contain carbon as a constituent element.

3. The method of producing an epitaxial silicon wafer, according to claim 2, wherein the cluster ions contain at least two kinds of elements including carbon as constituent elements.

4. The method of producing an epitaxial silicon wafer, according to claim 1, wherein after the first step, the silicon wafer is transferred into an epitaxial growth apparatus to be subjected to the second step without heat treating the silicon wafer for recovering its crystallinity.

5. The method of producing an epitaxial silicon wafer, according to claim 1, wherein in the first step, the silicon wafer is irradiated with the cluster ions such that the peak of a concentration profile of the constituent element in the depth direction of the modifying layer lies at a depth within 150 nm from the surface of the silicon wafer.

6. The method of producing an epitaxial silicon wafer, according to claim 5, wherein the first step is performed under the conditions of acceleration voltage per one carbon atom:

50 keV/atom or less, cluster size;

100 or less, and carbon dose;

1×

10¹⁶ atoms/cm² or less.

7. The method of producing an epitaxial silicon wafer, according to claim 5, wherein the first step is performed under the conditions of:

acceleration voltage per one carbon atom;

40 keV/atom or less, cluster size;

60 or less, and carbon dose;

5×

10¹⁵ atoms/cm² or less.

13. A method of producing a solid-state image sensing device, wherein a solid-state image sensing device is formed on the epitaxial silicon layer, located in the surface portion of the epitaxial wafer fabricated by the producing method according to claim 1.

8. A semiconductor epitaxial wafer, comprising:

a silicon wafer free of dislocation clusters and COPs;

a modifying layer formed from a certain element in a surface portion of the silicon wafer; and

an epitaxial layer on the modifying layer,

wherein the full width half maximum of a concentration profile of the certain element in the depth direction of the modifying layer is 100 nm or less.

9. The epitaxial silicon wafer according to claim 8, wherein the peak of the concentration profile in the modifying layer lies at a depth within 150 nm from the surface of the silicon wafer.

10. The epitaxial silicon wafer according to claim 8, wherein the peak concentration of the concentration profile of the modifying layer is 1×

10¹⁵ atoms/cm³ or more.

11. The epitaxial silicon wafer according to claim 8, wherein the certain element includes carbon.

12. The epitaxial silicon wafer according to claim 11, wherein the certain element includes at least two kinds of elements including carbon.

14. A method of producing a solid-state image sensing device, wherein a solid-state image sensing device is formed on the epitaxial silicon layer, located in the surface portion of the epitaxial silicon wafer according to claim 8.