4H-SiCÌÎS transistors with accumulation-type n-channel: spatial distribution of free electrons under the gate

 

P. À. Ivanov¹, À. S. Potapov¹, S. B. Rybalka², À. À. Malakhanov²

¹ Ioffe Institute, Polytekhnicheskaya St. 26, St. Petersburg, 194021, Russia

²Bryansk State Technical University, 50 let Oktyabrya Blvd. 7, Bryansk, 241035, Russia

 

The paper is received on June 7, 2017

 

Abstract. The spatial distributions of free electrons under the gate of normally closed 4H-SiC MOS transistors with accumulation-type n-channel (ACCUFETs) have been theoretically calculated. Two types of ACCUFETs are compared in which the n-channel is initially pinched-off  by the depletion region of the p⁺-n-juction's or MOS-gate. It has been shown that the wider spatial distribution is realized in the second case. From the point of view of effective mobility of electrons, transistors of the second type has to be superior to the first one. In this case it is possible to expect that the effective mobility of electrons in the conductive channel will approach to mobility in the bulk. It must be admitted that the regulation of threshold voltage of such transistors is limited to possibility of the choice of metals with the necessary work functions. In addition, the charged traps in oxide and at the oxide-semiconductor interface maybe have a strong effect on threshold voltage of such transistors.

Key words: silicon carbide, MOS transistors, p⁺-n-junction, electron mobility.

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For citation:

P.À.Ivanov, À.S.Potapov, S B.Rybalka, À.À.Malakhanov. 4H-SiC ÌÎS transistors with accumulation-type n-channel: spatial distribution of free electrons under the gate. Zhurnal Radioelektroniki - Journal of Radio Electronics, 2017, No. 6. Available at http://jre.cplire.ru/jre/jun17/7/text.pdf. (In Russian)