Patent ID: 11862720
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method for forming a semiconductor device, the method comprising:
depositing a rough buffer layer overlying and directly contacting a silicon substrate, wherein the rough buffer layer has a bottom surface and a top surface that each has alternating peaks and valleys at completion of the depositing of the rough buffer layer;
depositing an aluminum nitride buffer layer overlying and directly contacting the rough buffer layer at the top surface of the rough buffer layer;
depositing a gallium nitride layer and an aluminum gallium nitride layer directly contacting each other at a heterojunction and both overlying the aluminum nitride buffer layer;
forming a source electrode and a drain electrode overlying the gallium nitride layer and the aluminum gallium nitride layer; and
forming a gate electrode overlying the gallium nitride layer and the aluminum gallium nitride layer, laterally between the source electrode and the drain electrode;
wherein the rough buffer layer is a semiconductor material with a band gap within 0.7 electron volts (eV) of a band gap of the silicon substrate.