Influence of Buffer Layer on DC and RF Performance of 4H SiC MESFET
Influence of Buffer Layer on DC and RF Performance of 4H SiC MESFET
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DOI：
10.4028/www.scientific.net/msf.457-460.1193
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发表时间：
2004-06
期刊：
影响因子：
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通讯作者：
A. Los;M. Mazzola;D. Kajfez;B. Mcdaniel;C.E. Smith;J. Kretchmer;L. Rowland;J. Casady
中科院分区：
文献类型：
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作者：
A. Los;M. Mazzola;D. Kajfez;B. Mcdaniel;C.E. Smith;J. Kretchmer;L. Rowland;J. Casady
比较了半绝缘衬底上制作的功率4 H-SiC MESFET的直流和射频特性，以及有和没有低掺杂p型缓冲层。输出导纳和栅极接触热谱测量进行分析载流子捕获现象在衬底沟道界面。测量表明，在没有缓冲层的器件中，在沟道-衬底界面处钒受体捕获自由载流子。在具有缓冲器的器件的情况下，既没有观察到输出或栅极导纳的频散，也没有观察到栅极电容瞬态。在0.045-5 GHz的频率范围内的MESFER上进行S参数的测量。测量结果被用来建立MESFET的等效电路。
DC and RF characteristics are compared for power 4H-SiC MESFETs fabricated on semi-insulating substrates, with and without a low-doped p-type buffer layer. Output admittance and gate contact thermal spectroscopy measurements are performed to analyze carrier trapping phenomena at the substrate-channel interface. Measurements indicate trapping of free carriers by vanadium acceptor at the channel-substrate interface in devices without the buffer. In the case of devices with the buffer, neither the frequency dispersion of the output or gate admittance nor the gate capacitance transient was observed. Measurements of S-parameters are performed on the MESFETs in the frequency range 0.045-5 GHz. Measurement results are used to build MESFET equivalent circuit.