A novel 4H-SiC MESFET with double upper gate and recessed p-buffer

Highlights

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A novel 4H-SiC structure named DURP MESFET is proposed.

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A double upper gate and a recessed p-buffer are employed in the DURP MESFET.

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DC and RF characteristics are simulated.

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Compared with DR MESFET, DURP MESFET obtains higher drain current and breakdown voltage.

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An evident decrease in gate-source capacitance of DURP MESFET is achieved.

Abstract

A novel structure named 4H-SiC metal semiconductor field effect transistor with double upper gate and recessed p-buffer (DURP MESFET) is proposed and simulated in this paper. The increase in the saturation drain current and the breakdown voltage, and the decrease in the gate-source capacitance are achieved compared with those of DR MESFET, which is result from the reduction of the depletion region under the gate by the introduction of a double upper gate. The negative influence of the double upper gate on trans-conductance is suppressed by employing a recessed p-buffer. With the optimal size, the height of the upper gate Z = 0.10 μm, the depth and width of the recessed p-buffer of 0.05 μm and 0.35 μm, superior DC and RF characteristics for the proposed structure can be obtained, such as a 22.5% increase in the saturation drain current and a 17.9% increase in the breakdown voltage compared to the DR MESFET. The gate-source capacitance is 0.439 pF/mm compared to 0.573 pF/mm of DR MESFET by reference to simulated results, which would lead to the DURP MESFET has excellent RF performance.

Keywords

• 4H; 
• -SiC MESFET; 
• Double upper gate; 
• Recessed p-buffer; 
• Drain current; 
• Gate-source capacitance
• • • source:sciencedirect
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