Promos Technologies, Inc

Mosel Vitelic Corporation

Dong Jun Kim

Jin-Ho Kim

Chia-Shun Hsiao

Chuck Jang

Daniel Wang

Chunchieh Huang

Hua Ji

Substrate isolation trench () are formed in a semiconductor substrate (). Dopant (e.g. boron) is implanted into the trench sidewalls by ion implantation to suppress the current leakage along the sidewalls. During the ion implantation, the transistor gate dielectric () faces the ion stream, but damage to the gate dielectric is annealed in subsequent thermal steps. In some embodiments, the dopant implantation is an angled implant. The implant is performed from the opposite sides of the wafer, and thus from the opposite sides of each active area. Each active area includes a region implanted from one side and a region implanted from the opposite side. The two regions overlap to facilitate threshold voltage adjustment.

Substrate isolation in integrated circuits

A method and structure are provided with reduced gate wrap around to advantageously control for threshold voltage and increase stability in semiconductor devices. A spacer is provided aligned to field dielectric layers to protect the dielectric layers during subsequent etch processes. The spacer is then removed prior to subsequently forming a part of a gate oxide layer and a gate conductor layer. Advantageously, the spacer protects the corner area o the field dielectric and also allows for enhanced thickness of the gate oxide near the corners.

Corner protection to reduce wrap around

A method and structure to form shallow trench isolation regions without trench oxide grooving is provided. In particular, a method includes a two-step oxide process in which an oxide liner lines the inside surface of a trench and the trench is filled with a bulk oxide layer, preferably using a high density plasma chemical vapor deposition (HDP-CVD) process. The oxide liner and the bulk oxide layer are formed to have similar etch rates. Thus, when etching the oxide liner and the bulk oxide layer between stack structures, a common dielectric top surface is formed that is substantially planar and without grooves.

Trench isolation without grooving

Method of forming trench isolation without grooving

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San Jose, CA, United States of America

Dong Jun Kim