Transistors with high concentration of boron doped germanium

US8901537B2 · kind B2 · utility

Assignee

• Intel Corporation · US

Inventors

• Anand S. Murthy · Beaverton, US
• Glenn A. Glass · Portland, US
• Tahir Ghani · Portland, US
• Ravi Pillarisetty · Portland, US
• Niloy Mukherjee · Beaverton, US
• Jack T. Kavalieros · Portland, US
• Roza Kotlyar · Portland, US
• Willy Rachmady · Beaverton, US
• Mark Liu · West Linn, US

Key dates

• Filing date: Dec 21, 2010
• Grant date: Dec 2, 2014
• Expiry date: Sep 1, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/853
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Techniques are disclosed for forming transistor devices having source and drain regions with high concentrations of boron doped germanium. In some embodiments, an in situ boron doped germanium, or alternatively, boron doped silicon germanium capped with a heavily boron doped germanium layer, are provided using selective epitaxial deposition in the source and drain regions and their corresponding tip regions. In some such cases, germanium concentration can be, for example, in excess of 50 atomic % and up to 100 atomic %, and the boron concentration can be, for instance, in excess of 1E20 cm−3. A buffer providing graded germanium and/or boron concentrations can be used to better interface disparate layers. The concentration of boron doped in the germanium at the epi-metal interface effectively lowers parasitic resistance without degrading tip abruptness. The techniques can be embodied, for instance, in planar or non-planar transistor devices.