Method of implanting silicon through a polysilicon gate for punchthrough control of a semiconductor device

Abstract

Abstract A region of damaged silicon is exploited as a gettering region for gettering impurities in a silicon substrate. The region of damaged silicon is formed between source and drain regions of a device by implanting silicon atoms into the silicon substrate after the formation of a gate electrode of the device. The damaged region is subsequently annealed and, during the annealing process, dopant atoms such as boron segregate to the region, locally increasing the dopant concentration in the region. The previously damaged region is in a location that determine the punchthrough characteristics of the device. The silicon implant for creating a gettering effect is performed after gate formation so that the region immediately beneath the junction is maintained at a lower dopant concentration to reduce junction capacitance. Silicon is implanted in the vicinity of a polysilicon gate to induce transient-enhanced diffusion (TED) of dopant atoms such as boron or phosphorus for control of punchthrough characteristics of a device. A punchthrough control implant is performed following formation of gate electrodes on a substrate using a self-aligned gettering implant.

Inventors

• 👤 Mark I. Gardner
• 👤 Derick J. Wristers
• 👤 Robert Dawson
• 👤 H. Jim Fulford, Jr.
• 👤 Frederick N. Hause
• 👤 Mark W. Michael
• 👤 Bradley T. Moore

Bibliographic Details