Cypress Semiconductor Corporation

Silicon General Corporation

Sang S Kim

Krishnaswamy Ramkumar

Sharmin Sadoughi

Pamela Shiell Trammel

Avner Shelem

Richard H Belanger

A method of forming a field oxide or isolation region in a semiconductor die. A nitride layer (over an oxide layer disposed over a substrate) is patterned and subsequently etched so that the nitride layer has a nearly vertical sidewall. The oxide layer and the substrate in the isolation region are etched to form a recess in the substrate having a sloped surface with respect to the nearly vertical sidewall of the nitride layer. A field oxide is then grown in the recess using a high pressure, dry oxidizing atmosphere. The sloped sidewall of the substrate effectively moves the face of the exposed substrate away from the edge of the nitride layer sidewall. Compared to non-sloped techniques, the oxidation appears to start with a built-in offset from the patterned etch. This leads to a reduction of oxide encroachment and a nearly non-existent bird's beak. The desirable range of slopes for the substrate sidewall is approximately 50&deg;-80&deg; with respect to a nearly planar surface of the substrate in the recess.

Method and structure for isolating integrated circuit components and/or semiconductor active devices

A method for forming a dielectrically isolated semiconductor devices on a semiconductor substrate. An epitaxial layer is grown on a wafer having a thin buried oxide layer. Trench regions are etched through the epitaxial layer to the underlying oxide layer. A dielectric isolation layer is formed on the sidewalls of the trench regions so as to isolate an active region of the epitaxial semiconductor material. The trenches are etched to the underlying semiconductor substrate and the semiconductor material is selectively epitaxially regrown in the trench regions. Semiconductor devices are formed in the isolated active regions. Contacts are made to the active regions of the semiconductor device and to the wafer substrate through the epitaxially regrown trench regions.

Method for forming dielectrically isolated semiconductor devices with

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Laguna Hills, CA, United States of America

Sang S Kim