Stanford Advisors

All Publications

  • Low Thermal Budget Growth of Near-Isotropic Diamond Grains for Heat Spreading in Semiconductor Devices ADVANCED FUNCTIONAL MATERIALS Malakoutian, M., Zheng, X., Woo, K., Soman, R., Kasperovich, A., Pomeroy, J., Kuball, M., Chowdhury, S. 2022
  • Nanoporous GaN on p-type GaN: A Mg out-diffusion compensation layer for heavily Mg-doped p-type GaN. Nanotechnology Lee, K. J., Nakazato, Y., Chun, J., Wen, X., Meng, C., Soman, R., Noshin, M., Chowdhury, S. 2022


    Embeddingp-type gallium nitride (p-GaN) with controlled Mg out-diffusion in adjacent epitaxial layers is a key for designing various multi-junction structures with high precision and enabling more reliable bandgap engineering of III-nitride-based optoelectronics and electronics. Here, we report, for the first time, with experimental evidence how nanoporous GaN (NP GaN) can be introduced as a compensation layer for the Mg out-diffusion fromp-GaN. NP GaN onp-GaN provides an ex-situ-formed interface with oxygen and carbon impurities, compensating Mg out-diffusion fromp-GaN. To corroborate our findings, we used two-dimensional electron gas (2DEG) formed at the interface of AlGaN/GaN as the indicator to study the impact of the Mg out-diffusion from underlying layers. Electron concentration evaluated from the capacitance-voltage measurement shows that 9 * 1012cm-2of carriers accumulate in the AlGaN/GaN 2DEG structure grown on NP GaN, which is the almost same number of carriers as that grown with nop-GaN. In contrast, 2DEG onp-GaN without NP GaN presents 9 * 109cm-2of the electron concentration, implying 2DEG structure is depleted by Mg out-diffusion. The results address the efficacy of NP GaN and its' role in successfully embeddingp-GaN in multi-junction structures for various state-of-the-art III-nitride-based devices.

    View details for DOI 10.1088/1361-6528/ac91d7

    View details for PubMedID 36103775

  • Vertical Ga2O3 MOSFET With Magnesium Diffused Current Blocking Layer IEEE ELECTRON DEVICE LETTERS Zeng, K., Soman, R., Bian, Z., Jeong, S., Chowdhury, S. 2022; 43 (9): 1527-1530
  • A study on MOCVD growth window for high quality N-polar GaN for vertical device applications SEMICONDUCTOR SCIENCE AND TECHNOLOGY Soman, R., Noshin, M., Chowdhury, S. 2022; 37 (9)
  • A systematic study of the regrown interface impurities in unintentionally doped Ga-polar c-plane GaN and methods to reduce the same SEMICONDUCTOR SCIENCE AND TECHNOLOGY Noshin, M., Soman, R., Xu, X., Chowdhury, S. 2022; 37 (7)