Growth and Characterization of Gallium-Oxide Epitaxial Films for High Performance Contact Structures
Abstract
Gallium oxide (Ga2O3) is an ultra-wide band gap semiconductor that has immense promise for high efficiency electronics that can operate in extreme conditions. This emerging semiconductor technology offers unique properties and practical achievements that give it notable advantages for future generations of advanced high-power-frequency-temperature electronics and optoelectronics operating in the ultraviolet (UV) region that are critical to the U.S. defense and national security interests. The existence of different phases, or polymorphs, of Ga2O3 presents both a challenge and an opportunity to understand how to fabricate highly ordered Ga2O3 films with control over phase, structure and morphology. Electrical, chemical, morphological, and other properties of metal-Ga2O3 contacts to these Ga2O3 polymorphs often limit device performance. To address these issues, investigators at the University of Texas at El Paso (UTEP) and Carnegie Mellon University (CMU) propose to grow and characterize ?-Ga2O3 and ?-Ga2O3 epitaxial layers for use in high-performance contact structures. Contacts will be formed on homoepitaxial ?-Ga2O3 and heteroepitaxial ?-Ga2O3 layers deposited using halide vapor phase epitaxy (HVPE). Highly-doped ?-Ga2O3 interlayers will be grown using pulsed laser deposition (PLD) to achieve low-resistance ohmic contacts. Schottky contact studies will focus on Beta- Ga2O3 epilayers to understand how the interfacial physics and chemistry affect Schottky barrier formation to this less investigated Ga2O3 polymorph. All of the Ga2O3 films and metal-Ga2O3 contacts will be evaluated as a function of deposition and processing conditions using a variety of techniques, including, x-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, optical measurements, and current-voltage measurements. Students in this project will develop technical and professional skills relevant in the semiconductor industry. Students from UTEP will spend a summer and-or full spring-fall semester at CMU to perform research using advanced facilities in the Bertucci Nanotechnology Laboratory. The world-class facilities at CMU will substantially enhance the research capabilities of the PI and students at UTEP, which is primarily a Hispanics serving minority institution. The project will further provide unique opportunities for cross fertilization of ideas, student mentoring, and interdisciplinary training. Furthermore, the students will also conduct summer internships at the Air Force Research Laboratory (AFRL). The students will specifically work with experts in PLD, Ga2O3, and other oxide thin films. More broadly, the results of this research program will hasten the development of devices based on Ga2O3. As such, the proposed project is highly relevant to the mission and scientific programs of the Department of Defense (DoD), especially the Air Force Office of Scientific Research (AFOSR), which has need for ultra-high efficiency electronics that can operate under extreme conditions.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502110360
Entities
People
- Ramana Chintalapalle
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Texas at El Paso