Multiple precipitation doping process

US6300228A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• James W. Adkisson · Jericho, US
• James A. Bruce · Williston, US
• John J. Ellis-Monaghan · Grand Isle, US
• Randy W. Mann · Jericho, US
• Edward J. Nowak · South Burlington, US
• Kirk D. Peterson · Jericho, US

Key dates

• Filing date: Aug 30, 1999
• Grant date: Oct 9, 2001
• Expiry date: Aug 30, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/2255
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A multiple precipitation doping process for doping a semiconductor substrate (30) starts with forming an amorphous region (32) in the substrate (30). Through multiple laser exposures, multiple dopant precipitation films (52, 53) are formed on corresponding portions (34, 37) of the major surface (31) of the substrate (30) overlying the amorphous region (32). The substrate (30) is then annealed. The annealing process melts the amorphous region (32) and allows the dopants precipitated on the major surface (31) to diffuse into the substrate (30). The annealing process also crystallizes the semiconductor material the amorphous region (32). The substrate (30) becomes a single crystal semiconductor substrate with multiple doped regions (54, 57) therein. The depth of the doped regions (54, 57) is substantially equal to the depth of the amorphous region (32) before annealing.