Extraction of the active acceptor concentration in (pseudo-) vertical GaN MOSFETs using the body-bias effect. (September 2019)

• Record Type: Journal Article
• Authors: Hentschel, R.; Wachowiak, A.; Großer, A.; Kotzea, S.; Debald, A.; Kalisch, H.; Vescan, A.; Jahn, A.; Schmult, S.; Mikolajick, T.
• Is Part Of: Microelectronics journal. Volume 91(2019)
• Page Start: 42
• Page End: 45
• Publication Date: 2019-09
• Subjects: Gallium nitride -- Pseudo-vertical -- MOSFET -- Power semiconductor -- High-k dielectric -- Body bias -- Trench gate -- Magnesium doping; Microelectronics -- Periodicals; Microélectronique -- Périodiques; Microelectronics; Electronic journals; Journals - contents and abstracts; Periodicals; 621.3805
• DOI: 10.1016/j.mejo.2019.07.011
• Languages: English
• ISSNs: 0959-8324

Abstract

Abstract: We report and discuss the performance of an enhancement mode n-channel pseudo-vertical GaN metal oxide semiconductor field effect transistor (MOSFET). The trench gate structure of the MOSFET is uniformly covered with an Al2 O3 dielectric and TiN electrode material, both deposited by atomic layer deposition (ALD). Normally-off device operation is demonstrated in the transfer characteristics. Special attention is given to the estimation of the active acceptor concentration in the Mg doped body layer of the device, which is crucial for the prediction of the threshold voltage in terms of device design. A method to estimate the electrically active dopant concentration by applying a body bias is presented. The method can be used for both pseudo-vertical and truly vertical devices. Since it does not depend on fixed charges near the channel region, this method is advantageous compared to the estimation of the active doping concentration from the absolute value of the threshold voltage.