Ohmic contact structures on β-Ga2O3 with n+ β-Ga2O3 pulsed laser deposition layers
Abstract
Thin (40–150 nm), highly doped n+ (1019–1020 cm−3) Ga2O3 layers deposited using pulsed laser deposition (PLD) were incorporated into Ti/Au ohmic contacts on (001) and (010) β-Ga2O3 substrates with carrier concentrations between 2.5 and 5.1 × 1018 cm−3. Specific contact resistivity values were calculated for contact structures both without and with a PLD layer having different thicknesses up to 150 nm. With the exception of a 40 nm PLD layer on the (001) substrate, the specific contact resistivity values decreased with increasing PLD layer thickness: up to 8× on (001) Ga2O3 and up to 16× on (010) Ga2O3 compared with samples without a PLD layer. The lowest average specific contact resistivities were achieved with 150 nm PLD layers: 3.48 × 10−5 Ω cm2 on (001) Ga2O3 and 4.79 × 10−5 Ω cm2 on (010) Ga2O3. Cross-sectional transmission electron microscopy images revealed differences in the microstructure and morphology of the PLD layers on the different substrate orientations. This study describes a low-temperature process that could be used to reduce the contact resistance in Ga2O3 devices.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 01, 2023
- Source ID
- 10.1116/6.0002620
Entities
People
- Elizabeth V. Favela
- Francelia Sanchez Escobar
- Hyung Min Jeon
- Kevin Leedy
- Kun Zhang
- Lisa M. Porter
- Ramana Chintalapalle
- Szu-Wei Tung
Organizations
- Air Force Office of Scientific Research
- Air Force Research Laboratory
- Carnegie Mellon University
- KBR, Inc.
- University of Texas at El Paso