Process for forming polysilicon/germanium thin films without germanium outgassing
AssigneeAdvanced Micro Devices, Inc.
InventorBin Yu
Life of this patent
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Abstract
An ultra-large scale integrated (ULSI) circuit includes MOSFETs which have different threshold voltages and yet have the same channel characteristics. The MOSFETs utilize gate structures with heavily doped polysilicon and germanium material. The polysilicon and germanium materials or thin films are manufactured by low pressure chemical vapor deposition. A silicon buffer layer and oxide cap is used to prevent germanium outgassing.
Claims20
A method of manufacturing an integrated circuit, comprising:
- providing semiconductor and germanium thin film above a top surface of a substrate utilizing a semiconductor source and a germanium source;
- reducing the germanium source while utilizing the semiconductor source to form a semiconductor buffer layer above the semiconductor and germanium thin film;
- and
- oxidizing at least a portion of the semiconductor buffer layer;
- and
- providing spacers on side walls of the thin film.
A method of manufacturing a silicon and germanium thin film comprising steps of:
- depositing a germanium and silicon material on a top surface of a substrate utilizing a silicon gas source and a germanium gas source;
- turning the germanium gas source off while leaving the silicon gas source on to form a silicon buffer layer over the germanium and silicon material;
- and
- oxidizing the silicon buffer layer to form an oxide layer above the silicon buffer layer.
A method of providing a polysilicon and germanium thin film for an integrated circuit, the method comprising:
- providing a silicon and germanium layer above a substrate;
- providing a silicon buffer layer above the silicon and germanium layer;
- and
- oxidizing the silicon layer to form a silicon oxide layer above the silicon buffer layer.
Dependencies are inferred from the claim text.