Device Performance and Reliability Improvements of AlGaN/GaN/Si MOSFET Using Defect-Free Gate Recess and Laser Annealing
Abstract
AlGaN/GaN high electron mobility transistors are promising for high frequency and high power application due to their unique properties. High-k dielectrics, such as Al2O3 and HfO2, are attractive materials which suppresses the gate leakage current of AlGaN/GaN high electron mobility transistors. Since the interface quality of AlGaN and high k dielectrics are critical to device performance, such as the threshold voltage and interface state density \201Dit\202, it is therefore necessary to understand that the relationship between interface chemistry and device performance is fundamental for examining optimization strategies for device applications. Firstly, the impact of various chemical pretreatments on AlGaN surface is studied. Then the interfaces formed upon atomic layer deposition \201ALD\202 of Al2O3 and HfO2 are investigated using in situ X-ray photoelectron spectroscopy \201XPS\202. The impacts of ALD of Al2O3 and HfO2 on native AlGaN are studied by capacitance voltage characterization. The XPS and device results uncover a high density of interface states. In situ N2 forming gas and O2 plasma pretreatments prior to ALD as optimization strategies are investigated using in situ XPS, LEED and C-V characterizations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 15, 2015
- Accession Number
- ADA621256
Entities
People
- Robert M Wallace
Organizations
- University of Texas at Dallas