Body contact SOI transistor structure and method of making

摘要

The present invention puts forward a body-contact SOI transistor structure and method of making. The method comprises: forming a hard mask layer on the SOI; etching an opening exposing SOI bottom silicon; wet etching an SOI oxide layer through the opening; depositing a polysilicon layer at the opening followed by anisotropic dry etching; depositing an insulating dielectric layer at the opening followed by planarization; forming a gate stack structure by deposition and etching, and forming source/drain junctions of the transistor using ion implantation. By using the present invention, body contact for SOI field-effect transistors can be effectively formed, thereby eliminating floating-body effect in the SOI field-effect transistors, and improving heat dissipation capability of the SOI transistors and associated integrated circuits.

主权项

1. A method of making a body-contact SOI transistor structure on a silicon-on-insulator (SOI) substrate, the SOI substrate including upper silicon on an insulator layer on bottom silicon, the method comprising:
forming an opening through the upper silicon and the insulator layer, the opening exposing the bottom silicon; laterally etching the insulator layer underneath the upper silicon through the opening to create recessed regions in the opening underneath the upper silicon; filling the recessed regions with a polysilicon layer such that the polysilicon layer connects the upper silicon and the bottom silicon; filling the opening with an insulating dielectric layer; forming a gate stack over the SOI substrate, the gate stack having a first portion covering the opening and a second portion extending from the first portion and covering an area of the upper silicon across a middle portion of an active region of the body-contact SOI transistor; and forming source/drain junctions of the body-contact SOI transistor structure on opposite sides of the gate stack using self-aligned processes such that one of the source/drain junctions is on a first side of the opening while the other one of the source/drain junctions is on a second side of the opening opposite to the first side of the opening.