Promos Technologies, Inc

Hsio-Lei Wang

Hung-Kwei Liao

Jesse Chung

A method of forming a buried strap comprising the following sequential steps. A substrate having a pad oxide layer formed thereover is provided. A masking layer is formed over the pad oxide layer. The masking layer, pad oxide layer and substrate are etched to form a trench within the substrate. The trench having an outer sidewall and an upper portion. The upper portion of the trench is lined with a collar. A poly plate is formed within the trench. The poly plate and collar are etched below the substrate to form a recessed poly plate and a recessed collar and exposing a portion of outer sidewall of trench. Ions are implanted into the substrate through exposed outer sidewall of trench by gas phase doping. A SiN sidewall layer is formed over the exposed outer sidewall of trench at a temperature sufficient to diffuse the implanted ions further into the substrate to form the buried strap.

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Tainan, Taiwan

Hsio-Lei Wang