Taiwan Semiconductor Manufacturing Comp. Ltd.

Yan-Ting Lin

Yen-Ru Lee

Chun Hsiung Tsai

Chii-Horng Li

Chih-Yun Chin

Pei-Ren Jeng

Clement Hsingjen Wann

Hsueh-Chang Sung

Chien-Wei Lee

Heng-Wen Ting

Tzu-Hsiang Hsu

Roger Tai

Davie Liu

Jung-Chi Tai

Yee-Chia Yeo

Pang-Yen Tsai

Chia-Pin Lin

Yi-Tang Lin

Wei-Yuan Lu

Chien-Chang Su

Chien-I Kuo

Wei-Jen Lai

Cheng-Yan Zhan

A nano-FET and a method of forming is provided. In some embodiments, a nano-FET includes an epitaxial source/drain region contacting ends of a first nanostructure and a second nanostructure. The epitaxial source/drain region may include a first semiconductor material layer of a first semiconductor material, such that the first semiconductor material layer includes a first segment contacting the first nanostructure and a second segment contacting the second nanostructure, wherein the first segment is separated from the second segment. A second semiconductor material layer is formed over the first segment and the second segment. The second semiconductor material layer may include a second semiconductor material having a higher concentration of dopants of a first conductivity type than the first semiconductor material layer. The second semiconductor material layer may have a lower concentration percentage of silicon than the first semiconductor material layer.

Low Ge isolated epitaxial layer growth over nano-sheet architecture design for RP reduction

The embodiments of mechanisms for doping wells of finFET devices described in this disclosure utilize depositing doped films to dope well regions. The mechanisms enable maintaining low dopant concentration in the channel regions next to the doped well regions. As a result, transistor performance can be greatly improved. The mechanisms involve depositing doped films prior to forming isolation structures for transistors. The dopants in the doped films are used to dope the well regions near fins. The isolation structures are filled with a flowable dielectric material, which is converted to silicon oxide with the usage of microwave anneal. The microwave anneal enables conversion of the flowable dielectric material to silicon oxide without causing dopant diffusion. Additional well implants may be performed to form deep wells. Microwave anneal(s) may be used to anneal defects in the substrate and fins.

Mechanism for finFET well doping

In an embodiment, a device includes: a nanostructure; and a source/drain region adjoining a channel region of the nanostructure, the source/drain region including: a first epitaxial layer on a sidewall of the nanostructure, the first epitaxial layer including a germanium-free semiconductor material and a p-type dopant; a second epitaxial layer on the first epitaxial layer, the second epitaxial layer including a germanium-containing semiconductor material and the p-type dopant; and a third epitaxial layer on the second epitaxial layer, the third epitaxial layer including the germanium-containing semiconductor material and the p-type dopant.

Transistor source/drain regions and methods of forming the same

An embodiment is a semiconductor structure. The semiconductor structure includes a fin on a substrate. A gate structure is over the fin. A source/drain is in the fin proximate the gate structure. The source/drain includes a bottom layer, a supportive layer over the bottom layer, and a top layer over the supportive layer. The supportive layer has a different property than the bottom layer and the top layer, such as a different material, a different natural lattice constant, a different dopant concentration, and/or a different alloy percent content.

Supportive layer in source/drains of FinFET devices

Mechanism for FinFET well doping

An embodiment is a semiconductor structure. The semiconductor structure includes a substrate. A fin is on the substrate. The fin includes silicon germanium. An interfacial layer is over the fin. The interfacial layer has a thickness in a range from greater than 0 nm to about 4 nm. A source/drain region is over the interfacial layer. The source/drain region includes silicon germanium.

Interfacial layer between fin and source/drain region

Interfacial layer between Fin and source/drain region

In an embodiment, a device includes: a fin extending from a substrate; a gate stack over a channel region of the fin; and a source/drain region in the fin adjacent the channel region, the source/drain region including: a first epitaxial layer contacting sidewalls of the fin, the first epitaxial layer including silicon and germanium doped with a dopant, the first epitaxial layer having a first concentration of the dopant; and a second epitaxial layer on the first epitaxial layer, the second epitaxial layer including silicon and germanium doped with the dopant, the second epitaxial layer having a second concentration of the dopant, the second concentration being greater than the first concentration, the first epitaxial layer and the second epitaxial layer having a same germanium concentration.

Methods of forming semiconductor devices having plural epitaxial layers

The embodiments described above provide mechanisms of forming contact structures with low resistance. A strained material stack with multiple sub-layers is used to lower the Schottky barrier height (SBH) of the conductive layers underneath the contact structures. The strained material stack includes a SiGe main layer, a graded SiG layer, a GeB layer, a Ge layer, and a SiGe top layer. The GeB layer moves the Schottky barrier to an interface between GeB and a metal germanide, which greatly reduces the Schottky barrier height (SBH). The lower SBH, the Ge in the SiGe top layer forms metal germanide and high B concentration in the GeB layer help to reduce the resistance of the conductive layers underneath the contact structures.

Epitaxially grown stacked contact structure of semiconductor device

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Baoshan, China

Yan-Ting Lin