CHANNEL REPLACEMENT AND BIMODAL DOPING SCHEME FOR BULK FINFET THRESHOLD VOLTAGE MODULATION WITH REDUCED PERFORMANCE PENALTY

• US 20170179274A1
• Filed: 12/18/2015
• Published: 06/22/2017
• Est. Priority Date: 12/18/2015
• Status: Active Grant

• Current Assignee: Elpis Technologies Inc. (Wi-LAN Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Robison, Robert R., Karve, Gauri, Vega, Reinaldo A.
• Granted Patent: US 9,735,275 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 21/2253 by ion implantation
• CPC Class Codes: H01L 21/26513 of electrically active species
• CPC Class Codes: H01L 21/823431 with a particular manufacturing method of transistors with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 21/823821 with a particular manufacturing method of transistors with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 27/0924 including transistors with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/0638 for preventing surface leakage due to surface inversion layer, e.g. with channel stopper channel stoppers in combination with isolation region for integrated circuits H01L21/762
• CPC Class Codes: H01L 29/1054 with a variation of the composition, e.g. channel with strained layer for increasing the mobility
• CPC Class Codes: H01L 29/1083 with an inactive supplementary region, e.g. for preventing punch-through, improving capacity effect or leakage current
• CPC Class Codes: H01L 29/1608 Silicon carbide
• CPC Class Codes: H01L 29/161 including two or more of the elements provided for in group H01L29/16 , e.g. alloys H01L29/1604 takes precedence
• CPC Class Codes: H01L 29/165 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/20 including, apart from doping materials or other impurities, only AIIIBV compounds
• CPC Class Codes: H01L 29/205 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/36 characterised by the concentration or distribution of impurities in the bulk material within semiconductor regions H01L29/06
• CPC Class Codes: H01L 29/66537 using a self aligned punch through stopper or threshold implant under the gate region H01L29/66606 takes precedence
• CPC Class Codes: H01L 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/785 having a channel with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/7851 with the body tied to the substrate

Abstract

A method includes removing a top portion of a substrate after implantation of a punch through stopper into the substrate; epitaxially growing undoped material on the substrate, thereby forming a channel; filling a top portion of the channel with an intermediate implant forming a vertically bi-modal dopant distribution, with one doping concentration peak in the top portion of the channel and another doping concentration peak in the punch through stopper; and patterning fins into the channel and the punch though stopper to form a finFET structure.

Claims

10-20. -20. (canceled)

22-1. The method of claim 1, wherein the punch through stopper is disposed between an active fin and the substrate, wherein the active fin has a higher doping at a top of the active fin as compared to a bottom of the active fin.