US 6,787,451 B2 · Semiconductor device and manufacturing method thereof

Abstract

In a method for manufacturing an FET having a gate insulation film with an SiO2 equivalent thickness of 2 nm or more and capable of suppressing the leak current to {fraction (1/100)} or less compared with existent SiO2 films, an SiO2 film of 0.5 nm or more is formed at a boundary between an Si substrate (polycrystalline silicon gate) and a high dielectric insulation film, and the temperature for forming the SiO2 film is made higher than the source-drain activating heat treatment temperature in the subsequent steps. As such, a shifting threshold voltage by the generation of static charges or lowering of a drain current caused by degradation of mobility can be prevented so as to reduce electric power consumption and increase current in a field effect transistor of a smaller size.

Claims18

Dependent claims

A method for manufacturing a semiconductor device having a field effect transistor in which a metal oxide film of a higher dielectric constant than that of a silicon oxide film formed on a silicon substrate is used as a gate insulation film, comprising:

forming the metal oxide film on the silicon substrate;
forming a first silicon oxide film or a silicon oxynitride film with a thickness of 0.5 nm or more between the silicon substrate and the metal oxide film by a first heat treatment in an oxidative atmosphere at a first temperature;
forming a gate of the field effect transistor on the metal oxide film after the first heat treatment;
implanting impurity ions into source and drain regions in the silicon substrate;
and
activating the source and drain regions by a second heat treatment at a second temperature,
wherein the first temperature is equal to or more than the second temperature.

4 more elements

Dependencies are inferred from the claim text.

Semiconductor device and manufacturing method thereof

Life of this patent

Semiconductor device and manufacturing method thereof

Life of this patent

Abstract

Claims18