Gain improvement and microwave operation of 4H-SiC MESFET with a new recessed metal ring structure

A new multi-recessed 4H-SiC MESFET with recessed metal ring for RF embedded circuits is proposed (MR2-MESFET). The key idea in the proposed structure is based on the elimination of the spaces adjacent to gate and stopped the depletion region extending towards drain and source and the reduction of the channel thickness between gate and drain to increase breakdown voltage (V"B"R); meanwhile the elimination of the gate depletion layer extension to source/drain to decrease gate-source capacitance (C"g"s). The influence of multi-recessed drift region and recessed metal ring structures on the characteristics of the MR2-MESFET is studied by numerical simulation. The optimized results show that the V"B"R of the MR2-MESFET is 119% larger than that of the conventional 4H-SiC MESFET (C-MESFET); meanwhile maintain 85% higher saturation drain current. Therefore, the maximum output power density of the MR2-MESFET is 23.1W/mm compared to 5.5W/mm of the C-MESFET. Also, the cut-off frequency (f"T) and the maximum oscillation frequency (f"m"a"x) of 24.9 and 91.7GHz are obtained for the MR2-MESFET compared to 11 and 40GHz of the C-MESFET structure, respectively. The proposed MR2-MESFET shows a maximum stable gain (MSG) exceeding 23.6dB at 3.1GHz which is the highest gain yet reported for SiC MESFETs, showing the potential of this device for high power RF applications.

[2]  John D. Cressler,et al.  Comparison and optimization of edge termination techniques for SiC power devices , 2001, Proceedings of the 13th International Symposium on Power Semiconductor Devices & ICs. IPSD '01 (IEEE Cat. No.01CH37216).

[3]  Rusli,et al.  Improved performance of SiC MESFETs using double-recessed structure , 2006 .

[4]  L. Eastman,et al.  Gate field emission induced breakdown in power SiC MESFETs , 2003, IEEE Electron Device Letters.

[5]  Physical Simulation of Drain-Induced Barrier Lowering Effect in SiC MESFETs , 2005 .

[6]  Bo Zhang,et al.  Effects of a multi-recessed gate in microwave 4H-SiC power MESFETs , 2009, 2009 International Conference on Communications, Circuits and Systems.

[7]  High voltage (450 V) 6H-SiC lateral MESFET structure , 1996 .

[8]  H. Zirath,et al.  Fabrication and characterization of field-plated buried-gate SiC MESFETs , 2006, IEEE Electron Device Letters.

[9]  W.R. Van Dell,et al.  Floating metal rings (FMR), a novel high-voltage blocking technique , 1985, IEEE Electron Device Letters.

[10]  Bo Zhang,et al.  Improved double-recessed 4H-SiC MESFETs structure with recessed source/drain drift region , 2007 .

[11]  Takashi Shinohe,et al.  Parameters required to simulate electric characteristics of SiC devices for n-type 4H-SiC , 2004 .

[12]  Bo Zhang,et al.  High breakdown voltage 4H-SiC Schottky Barrier Diodes with floating metal rings for MMIC applications , 2006, 2006 8th International Conference on Solid-State and Integrated Circuit Technology Proceedings.

[13]  Yuming Zhang,et al.  Simulation study on field-plated buried gate-buried channel SiC MESFETs , 2009, 2009 IEEE International Conference of Electron Devices and Solid-State Circuits (EDSSC).

[14]  Bo Zhang,et al.  Asymmetric 3D tri-gate 4H-SiC MESFETs with a recessed drain drift region , 2009 .

[15]  S. Allen,et al.  4H-SiC MESFET with 65.7% power added efficiency at 850 MHz , 1997, IEEE Electron Device Letters.

[16]  A.W. Morse,et al.  S-band operation of SiC power MESFET with 20 W (4.4 W/mm) output power and 60% PAE , 2004, IEEE Transactions on Electron Devices.

[17]  Jae Bin Lee,et al.  Fabrication and characterization of 4H-SiC planar MESFETs , 2006 .

[18]  L. Eastman,et al.  Channel recessed 4H-SiC MESFETs with F/sub t/ of 14.5GHz and F/sub max/ of 40GHz , 2002, Proceedings. IEEE Lester Eastman Conference on High Performance Devices.

[19]  Bo Zhang,et al.  Improved Characteristics of 4H-SiC MESFET with Multi-recessed Drift Region , 2007, 2007 International Workshop on Electron Devices and Semiconductor Technology (EDST).

[20]  G. Boeck,et al.  Two-stage ultrawide-band 5-W power amplifier using SiC MESFET , 2005, IEEE Transactions on Microwave Theory and Techniques.

[22]  M. Levinson,et al.  Floating gates for avalanche suppression in MESFET's , 1992, IEEE Electron Device Letters.

[23]  Bo Zhang,et al.  Numerical analysis on the 4H-SiC MESFETs with a source field plate , 2007 .

[24]  Zhigang Li,et al.  Simulation of high-power 4H-SiC MESFETs with 3D tri-gate structure , 2007 .

[25]  R.D. Isaac,et al.  A Schottky-barrier diode with self-aligned floating guard ring , 1984, IEEE Transactions on Electron Devices.

[26]  M. Shur,et al.  Capacitance-voltage characteristics of microwave Schottky diodes , 1991 .

[27]  Krishna Shenai,et al.  Optimum semiconductors for high-power electronics , 1989 .

[28]  H. Mitlehner,et al.  SiC devices: physics and numerical simulation , 1994 .