SELF-ALIGNED BIPOLAR TRANSISTOR STRUCTURE

• US 20100127352A1
• Filed: 01/25/2010
• Published: 05/27/2010
• Est. Priority Date: 12/01/2006
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: El-Diwany, Monir, Sadovnikov, Alexei, Ramdani, Jamal
• Granted Patent: US 8,148,799 B2
• Time in Patent Office: Days
• US Class Current: 257/586
• CPC Class Codes: H01L 29/0817 of heterojunction bipolar transistors H01L29/7375 takes precedence
• CPC Class Codes: H01L 29/66242 Heterojunction transistors [HBT] with an active layer made of a group 13/15 material H01L29/66318
• CPC Class Codes: H01L 29/7378 comprising lattice mismatched active layers, e.g. SiGe strained layer transistors

Abstract

A bipolar transistor structure comprises a semiconductor substrate having a first conductivity type, a collector region having a second conductivity type that is opposite the first conductivity type formed in a substrate active device region defined by isolation dielectric material formed in an upper surface of the semiconductor substrate, a base region that includes an intrinsic base region having the first conductivity type formed over the collector region and an extrinsic base region having the second conductivity type formed over the isolation dielectric material, and a sloped in-situ doped emitter plug having the second conductivity type formed on the intrinsic base region.

Claims

1. A bipolar transistor structure comprising:

a semiconductor substrate having a first conductivity type;

a collector region having a second conductivity type that is opposite the first conductivity type formed in a substrate active device region defined by isolation dielectric material formed in an upper surface of the semiconductor substrate;

a base region that includes an intrinsic base region having the first conductivity type formed over the collector region and an extrinsic base region having the second conductivity type formed over the isolation dielectric material; and

a sloped in-situ doped emitter plug having the second conductivity type formed on the intrinsic base region.

3. The bipolar transistor structure of claim 1, and wherein the intrinsic base region and the extrinsic base region are formed from material selected from the group consisting of Si, SiGe, SiGe—

C and combinations thereof.

4. The bipolar transistor structure of claim 1, and wherein the in-situ doped emitter plug has an upper surface that is about 180 nm or less wide and a lower surface that is about 100-180 nm wide.

2. The bipolar transistor structure of 1, wherein the in-situ doped emitter plug comprises a lower monocrystalline silicon portion formed on the intrinsic base region and an upper polycrystalline silicon portion formed on the lower monocrystalline silicon portion.