US 5,327,007 A · Semiconductor substrate having a gettering layer

Abstract

A silicon wafer having a low concentration of oxygen and a silicon wafer having a high concentration of oxygen are joined and polished to prescribed thicknesses to form a semiconductor substrate according to the present invention. A region formed of the wafer having a low concentration of oxygen is used as a region where an element is formed, and a region formed of the wafer having a high concentration of oxygen produces a gettering effect on metal impurities and defects. As a DZ layer having a low concentration of oxygen, a wafer manufactured by an MCZ method or a wafer manufactured by a CZ method is used after being heat-treated at high temperature to diffuse oxygen outward. In another example, a damage layer, a polycrystalline silicon layer, an amorphous silicon layer or the like is formed between a DZ layer and an IG layer.

Claims9

Dependent claims

A semiconductor substrate, comprising:

p1 a first single crystalline silicon layer having a main surface where a semiconductor element is formed and a junction surface on an opposite side of said first single crystalline silicon layer, and uniformly having a first concentration of oxygen in the range of 2.times.10.sup.17 atoms/cm.sup.3 to 3.times.10.sup.17 atoms/cm.sup.3 along a direction perpendicular to the main surface;
and
a second single crystalline silicon layer joined to said junction surface of said first silicon crystalline silicon layer and uniformly having a second concentration of oxygen along a direction perpendicular to the main surface which is in the range of 16.times.10.sup.17 atoms/cm.sup.3 to 17.times.10.sup.17 atoms/cm.sup.3 along a direction vertical to the main surface.

Dependencies are inferred from the claim text.

Semiconductor substrate having a gettering layer

Life of this patent

Semiconductor substrate having a gettering layer

Life of this patent

Abstract

Claims9