MOCVD growth of InGaP/GaAs heterojunction bipolar transistors on 200 mm Si wafers for heterogeneous integration with Si CMOS

• Main Authors: Loke, Wan Khai, Lee, Kwang Hong, Wang, Yue, Tan, Chuan Seng, Fitzgerald, Eugene A., Yoon, Soon Fatt
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Electrical and electronic engineering; III–V/Si Integration; Bipolar Transistors
• Online Access: https://hdl.handle.net/10356/138539
• Institution: Nanyang Technological University

Heterojunction bipolar transistors (HBTs) with an In0.49Ga0.51P emitter and a GaAs base and collector were fabricated on epitaxial films grown directly onto Si substrates using a thin germanium (100%) buffer layer. All the materials (Ge, GaAs, In0.49Ga0.51P) were grown epitaxially using metal-organic chemical vapor deposition. The thin germanium buffer layer has a threading dislocation density (TDD) of ∼3 × 107 cm-2. The TDD of the active device layers does not worsen and is maintained at ∼2 × 107 cm-2, based on the density of dark spots detected in an electron-beam-induced current plan view image. Although the TDD is high, a DC current gain of 95 can be achieved by the In0.49Ga0.51P/GaAs HBT on a Si substrate. In addition, collector current and base current ideality factors (n c and n b) of 1.07 and 1.23, respectively, and average breakdown voltage (BV cbo) of 14.2 V can be realized. These results enable applications such as power amplifiers for mobile phone handsets and monolithic integration of HBTs with standard Si CMOS transistors on a common Si platform.