Multiple doping level bipolar junctions transistors and method for forming

US8143120B2 · kind B2 · utility

Assignee

• Agere Systems Inc. · US

Inventors

• Daniel Charles Kerr · Oak Ridge, US
• Michael Carroll · Orlando, US
• Amal Ma Hamad · Frisco, US
• Thiet The Lai · Orlando, US
• Roger W. Key · Orlando, US

Key dates

• Filing date: Feb 14, 2011
• Grant date: Mar 27, 2012
• Expiry date: Feb 14, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/859

Abstract

A process for forming bipolar junction transistors having a plurality of different collector doping densities on a semiconductor substrate and an integrated circuit comprising bipolar junction transistors having a plurality of different collector doping densities. A first group of the transistors are formed during formation of a triple well for use in providing triple well isolation for complementary metal oxide semiconductor field effect transistors also formed on the semiconductor substrate. Additional bipolar junction transistors with different collector doping densities are formed during a second doping step after forming a gate stack for the field effect transistors. Implant doping through bipolar transistor emitter windows forms bipolar transistors having different doping densities than the previously formed bipolar transistors. According to one embodiment of the present invention, bipolar junction transistors having six different collector dopant densities (and thus six different breakdown characteristics) are formed.