Chartered Semiconductor Manufacturing Ltd (corporation)

Qing Hua Zhong

Mei Sheng Zhou

Jian Xun Li

Bo Yu

Jian Hui Ye

A method of forming a shallow trench isolation trenches in a silicon substrate of an integrated circuit device is achieved. A silicon substrate is provided. A buffer layer is deposited overlying the silicon substrate. An etching endpoint layer is deposited overlying the buffer layer. A silicon layer is deposited layer overlying the etching endpoint layer. A photoresist layer is coated overlying the silicon layer. The photoresist layer is developed wherein the photoresist layer is removed where the trenches are planned. The silicon layer, the etching endpoint layer, and the buffer layer are etched through to expose the top surface of the silicon substrate. The silicon layer and the silicon substrate layer are etched until the top surface of the etching endpoint layer is exposed, and the trenches are thereby formed. The integrated circuit device is completed.

Method to form shallow trench isolation structures

A method for forming insulator filled, shallow trench isolation regions, with rounded corners, has been developed. The process features the use of a polymer coated opening, in an insulator layer, used as a mask to define the shallow trench region in silicon. After completion of the shallow trench formation the polymer spacers are removed, exposing a region of unetched semiconductor, that had been protected by the polymer spacers, during the shallow trench dry etching procedure. The sharp corner, at the intersection between the shallow trench and the unetched region of semiconductor, is then converted to a rounded corner, via thermal oxidation of exposed silicon surfaces. The polymer spacers also eliminate the top corner wraparound.

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Singapore, Singapore

Qing Hua Zhong