US Patent Application 18346511. SOURCE/DRAIN REGIONS OF FINFET DEVICES AND METHODS OF FORMING SAME simplified abstract

SOURCE/DRAIN REGIONS OF FINFET DEVICES AND METHODS OF FORMING SAME

Organization Name

Taiwan Semiconductor Manufacturing Co., Ltd.

Inventor(s)

Kun-Mu Li of Zhudong Township (TW)

Heng-Wen Ting of Pingtung (TW)

Yen-Ru Lee of Hsinchu (TW)

Hsueh-Chang Sung of Zhubei City (TW)

SOURCE/DRAIN REGIONS OF FINFET DEVICES AND METHODS OF FORMING SAME - A simplified explanation of the abstract

This abstract first appeared for US patent application 18346511 titled 'SOURCE/DRAIN REGIONS OF FINFET DEVICES AND METHODS OF FORMING SAME

Simplified Explanation

The patent application describes a method for forming a source/drain region in a semiconductor device.

• The method involves etching a semiconductor fin to create a recess that extends into the substrate.
• The source/drain region is formed by epitaxially growing three layers of silicon germanium (SiGe) on the sidewalls of the recess.
• The first SiGe layer has a germanium concentration of 10 to 40 atomic percent.
• The second SiGe layer has a higher germanium concentration than the first layer.
• The third SiGe layer has a lower germanium concentration than the second layer.

Original Abstract Submitted

A method includes forming a semiconductor fin over a substrate, etching the semiconductor fin to form a recess, wherein the recess extends into the substrate, and forming a source/drain region in the recess, wherein forming the source/drain region includes epitaxially growing a first semiconductor material on sidewalls of the recess, wherein the first semiconductor material includes silicon germanium, wherein the first semiconductor material has a first germanium concentration from 10 to 40 atomic percent, epitaxially growing a second semiconductor material over the first semiconductor material, the second semiconductor material including silicon germanium, wherein the second semiconductor material has a second germanium concentration that is greater than the first germanium concentration, and epitaxially growing a third semiconductor material over the second semiconductor material, the third semiconductor material including silicon germanium, wherein the third semiconductor material has a third germanium concentration that is smaller than the second germanium concentration.