Method of gettering using backside polycrystalline silicon

Abstract

An integrated circuit structure and method for manufacturing same which provides for gettering with a backside layer of polycrystalline silicon. The gettering of unwanted impurities from the integrated circuits involves the deposition of a polycrystalline silicon film on a semiconductor wafer prior to any or some high temperature processing steps. The semiconductor body is then subjected to the normal semiconductor processing steps to form semiconductor devices on the surface opposite to the surface having the polycrystalline silicon layer. During these high temperature processing steps, unwanted impurities such as copper, iron, nickel, sodium and potassium ions move toward and into the polycrystalline silicon layer and thereby away from the semiconductor devices. This produces improved yield in the integrated circuit process.

Dependencies are inferred from the claim text.