Method for forming hemispherical silicon grains on designated areas of silicon layer

US6187630A · kind A · utility

Assignee

• United Semiconductor Corp. · TW

Inventors

• Anchor Chen · Pingtung City, TW
• Shih-Ching Chen · Taipei, TW

Key dates

• Filing date: Feb 1, 1999
• Grant date: Feb 13, 2001
• Expiry date: Feb 1, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B12/033

Abstract

A method for forming hemispherical silicon grains on selected surfaces of a silicon layer includes the steps of forming a doped polysilicon layer over a substrate, and then forming amorphous spacers on the sidewalls of the doped polysilicon layer. Thereafter, an ion implantation is carried out to transform the upper portion of the doped polysilicon into an amorphous silicon layer. Finally, hemispherical silicon grains are formed on the upper surface of the amorphous layer lying above the polysilicon layer and the exposed surface of the amorphous spacers.