United Microelectronics Corp.

Yu-Kun Chen

Chin-Cheng Chien

Neng-Hui Yang

Hsiang-Ying Wang

Ya-Lun Cheng

Yu-Ren Wang

Chun-Yi Lee

Earic Liu

Gene Li

Yi-Cheng Chen

A method for fabricating an asymmetric semiconductor device is provided. A substrate formed with at least one base structure of MOSFET thereon is provided, wherein the base structure includes a gate over the substrate and a source extension and a drain extension in the substrate beside the gate. The base structure is then treated with an anisotropic annealing source inclined in the source-to-drain direction of the base structure relative to the normal of the substrate, such that one of the source and drain extensions is shadowed by the gate and the other is annealed more.

Method for fabricating asymmetric semiconductor device

A method for forming a junction region of a semiconductor device is disclosed. The steps of the method include providing a semiconductor substrate. A gate structure is formed on the semiconductor substrate. A dopant is implanted into the semiconductor substrate to form the junction region. An insulator layer is formed on the gate structure and the semiconductor substrate. A carbon-containing plasma treatment is performed to the insulator layer. A spacer is formed on a side-wall of the gate structure and the dopant is implanted into the semiconductor substrate to form a source/drain region next to the junction region. A heat treatment is performed to the semiconductor substrate.

Method for forming a junction region of a semiconductor device

A method of forming a transistor involves firstly forming at least one gate structure on a semiconductor substrate. Then, a surface cleaning process is performed. In the surface cleaning process, a chemical oxidation method is utilized for forming a first oxide layer on a surface of the semiconductor substrate not covered with the gate structure and the first oxide layer is removed subsequently. Finally, a selective epitaxial growth method is utilized for forming a first epitaxial layer on the surface of the semiconductor substrate.

Method of forming a transistor using selective epitaxial growth

A method for preventing to form a spacer undercut in SEG preclean process is provided. This present invention utilizes HFEG solution to etch the first spacer and the second spacer simultaneously, which can prevent from producing a spacer undercut, meanwhile; a native oxide layer upon a surface of a semiconductor substrate is removed. Hence, the clean surface on the semiconductor substrate is obtained. This method includes the steps as follows: Firstly, the native oxide layer upon the surface of the semiconductor substrate is removed by DHF (HF in deionized water) solution. Then, etching the first spacer and the second spacer at the same time by HFEG (HF diluted by ethylene glycol) solution. Also, the native oxide upon the semiconductor substrate is removed. Therefore, it obtains the clean semiconductor surface without a serious spacer undercut.

Method for preventing to form a spacer undercut in SEG pre-clean process

A method of manufacturing a MOS transistor is provided. A gate insulation layer and a conductive layer are sequentially formed over a substrate. A pre-amorphization implantation is carried out to amorphize the conductive layer. The conductive layer and the gate insulation layer are patterned to form a gate structure. A first spacer is formed on the sidewall of the gate structure. A second pre-amorphization implantation is carried out to amorphize a portion of the substrate. A doped source/drain extension region is formed in the substrate on each side of the first spacer. A second spacer is formed on the sidewall of the first spacer and then a doped source/drain region is formed in the substrate on each side of the second spacer. A solid phase epitaxial process is carried out to convert the doped source/drain extension region and the doped source/drain region into a source/drain terminal. In the pre-amorphization implantations, dopants having an ionic radius greater than the germanium ion are used.

Method of manufacturing metal-oxide-semiconductor transistor

The present invention provides a novel MOS transistor structure. The MOS transistor includes a gate electrode formed on a semiconductor substrate, and a gate oxide layer formed between the gate electrode and the semiconductor substrate. A spacer is formed on each sidewall of the gate electrode. A lightly doped source/drain extension is formed under the spacer with a raised epitaxial layer interposed between the spacer and the semiconductor substrate. The epitaxial layer, which is part of the lightly doped source/drain extension, has a lattice constant that is greater than the lattice constant of silicon crystal. The epitaxial layer serves as a solubility enhancement layer that is capable of increasing active boron concentration, thereby reducing sheet resistance of the source/drain extension. A heavily doped source/drain region is formed in the semiconductor substrate next to the edge of the spacer. A raised silicide layer is formed on the heavily doped source/drain region.

Growing community of inventors

Hsin-Chu, Taiwan

Yu-Kun Chen