US 7,679,166 B2 · Localized temperature control during rapid thermal anneal

Abstract

Disclosed herein are embodiments of a semiconductor structure and an associated method of forming the semiconductor structure with shallow trench isolation structures having selectively adjusted reflectance and absorption characteristics in order to ensure uniform temperature changes across a wafer during a rapid thermal anneal and, thereby, limit variations in device performance. Also disclosed are embodiments of another semiconductor structure and an associated method of forming the semiconductor structure with devices having selectively adjusted reflectance and absorption characteristics in order to either selectively vary the performance of individual devices (e.g., to form devices with different threshold voltages (Vt) on the same wafer) and/or to selectively optimize the anneal temperature of individual devices (e.g., to ensure optimal activation temperatures for n-type and p-type dopants during anneals).

Claims20

Dependent claims

A semiconductor structure comprising:

a substrate;
a device above said substrate, wherein said device comprises a first material with a first reflectivity;
and
a trench isolation region above said substrate and positioned laterally adjacent to said device, wherein said trench isolation region comprises:
a trench having sidewalls;
a second material with a second reflectivity in said trench;
and
a third material with a third reflectivity in contact with said second material,
wherein said third material does not extend laterally beyond said sidewalls, and
wherein a location of said third material relative to said second material and a ratio of an amount of said third material to an amount of said second material are predetermined such that said third material balances differences between said first reflectivity of said first material of said device and said second reflectivity of said second material of said trench isolation region in order to make reflectance and absorption characteristics of said device and said trench isolation region approximately uniform.

7 more elements

Dependencies are inferred from the claim text.

Localized temperature control during rapid thermal anneal

Life of this patent

Localized temperature control during rapid thermal anneal

Life of this patent

Abstract

Claims20