US 6,485,807 B1 · Silicon wafers having controlled distribution of defects, and methods of preparing the same

Abstract

A silicon wafer is provided having controlled distribution of defects, in which denuded zones having a sufficient depth inward from the surface of the wafer are combined with a high gettering effect in a bulk region of the wafer. In the silicon wafer, oxygen precipitates, which act as intrinsic gettering sites, show vertical distribution. The oxygen precipitate concentration profile from the top to the bottom surfaces of the wafer includes first and second peaks at first and second predetermined depths from the top and bottom surfaces of the wafer, denuded zones between the top and bottom surfaces of the wafer and each of the first and second peaks, and a concave region between the first and second peaks, which corresponds to a bulk region of the wafer. For such an oxygen precipitate concentration profile, the wafer is exposed to a rapid thermal annealing process in a gas mixture atmosphere containing nitrogen (N2) and argon (Ar) or N2 and hydrogen (H2), in a donor killing step during a wafering process.

Claims42

Dependent claims

A silicon wafer having a top surface, a bottom surface and an oxygen precipitate concentration profile therein between the top surface and the bottom surface, the oxygen precipitate concentration profile comprising;

first and second peaks at first and second predetermined depths from the top and bottom surfaces of the wafer, respectively;
a Denuded Zone (DZ) between the top surface of the wafer and the first peak and between the bottom surface of the wafer and the second peak;
and
a concave region between the first and second peaks.

1 more element

A method of manufacturing a silicon wafer, comprising:

performing a Rapid Thermal Annealing (RTA) process on a silicon wafer having a top surface and a bottom surface in an atmosphere of a gas mixture comprising a gas which has a vacancy injection effect and a gas which has an interstitial silicon injection effect on the top and bottom surfaces of the silicon wafer, to generate nucleation centers, which serve as oxygen precipitate growth sites during subsequent heat treatment, in a nucleation center concentration profile from the top surface to the bottom surface of the wafer, the nucleation center concentration profile comprising:
first and second peaks at first and second predetermined depths from the top and bottom spices of the wafer, respectively;
a region having a predetermined nucleation center concentration, between the top surface of the wafer and the first peak and between the bottom surface of the wafer and the second peak;
and
a concave region between the first and second peaks;
and
performing a subsequent heat treatment on the silicon wafer to form an oxygen precipitate concentration profile from the top surface to the bottom surface of the wafer, the oxygen precipitate concentration profile comprising:
first and second peaks at first and second predetermined depths from the top and bottom surfaces of the wafer, respectively;
a Denuded Zone (DZ) between the top surface of the wafer and the first peak and between the bottom surface of the wafer and the second peak;
and
a concave region between the first and second peaks.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application

09/702,503Filed 31 Oct 2000 · continuation in part

Priority

KR 97-429113 Feb 1997

Granted

26 Nov 2002

Term ends

Not estimatedThe source records don’t support an estimate.

Classification15 codes

C30B 15/206
Controlling or regulating: the thermal history of growing the ingot
C30B 15/14
Single-crystal growth by pulling from a melt, e.g. Czochralski method: heating of the melt or the crystallised materials
C30B 15/203
Controlling or regulating: the relationship of pull rate to axial thermal gradient
C30B 29/06
Elements: silicon

Family

Application60/063,086Us provisional application · filed 24 Oct 1997

Application08/989,591Parent of this division · filed 12 Dec 1997

Application09/320,102Parent of this continuation-in-part · filed 26 May 1999

Application09/320,210Parent of this continuation-in-part · filed 26 May 1999

Application09/454,675Parent of this continuation-in-part · filed 3 Dec 1999

Application60/172,352Us provisional application · filed 16 Dec 1999

Application09/454,675Parent of this division

US 6,045,610 AParent of this division

Application08/989,591Parent of this continuation-in-part

US 6,146,459 ARelated patent

US 6,251,184 B1Related patent

US 6,472,040 B1Related patent

US 6,485,807 B1This patent

From the US filing history. Foreign family members aren’t listed.

Silicon wafers having controlled distribution of defects, and methods of preparing the same

Life of this patent

Silicon wafers having controlled distribution of defects, and methods of preparing the same

Life of this patent

Abstract

Claims42