| 摘要 |
PURPOSE:To improve the breakdown voltage of a reversely biased Schottky barrier diode by gradually changing the carrier concentration in a second semiconductor layer so that the concentration can become lower on a Schottky electrode side and higher on a first semiconductor layer side. CONSTITUTION:The carrier concentration of an n<+>-type layer 1 is adjusted to >=10<18>cm<-3> and the carrier concentration of an n<+>-type layer 2 is adjusted so that the concentration can gradually vary between the lowest value NL and highest value NH, with the values NL and NH being selected out of a range from 10<14> to 10<17>cm<-3> (10<14>cm<-3=NL<NH<=10<17>cm<-3>). In the case the lowest carrier concentration NL is lower than 10<14>cm<-3>, the internal resistance of a Schottky barrier diode increases, and in the case the highest carrier concentration NH is higher than 10<17>cm<-3>, the breakdown voltage of a Schottky barrier diode drops when a reverse bias voltage is applied across the diode. When the carrier concentration of the n<->-type layer 2 is graded in such a way, the internal field intensity of the diode becomes weaker. Therefore, the breakdown voltage of the diode can be increased when reversely biased by grading the barrier concentration in the layer 2. |
