CONDUCTIVITY-MODULATED SILICON KECTIFIER 



989 



Ui with temperature. Fig. 7 gives a plot of this variation. The tempera- 

 ture variations of the other parameters are all small compared to that 

 of Wi . Thus, as in the case of the reverse currents, at sufficiently high 

 temperatures, the diffusion current makes the more important contribu- 

 tion. 



In the case of the forward current, I^c is relatively insensitive to the 

 distribution of impurities; therefore, the results of this section are im- 

 portant for all forward-biased diodes. In high-voltage diodes, to keep the 

 resistive voltage drop small, it is necessary to maintain high minority 

 carrier lifetime in the center region. The diffusion length of injected 



10' 



10'2 



10' 



lO'O 



o 



c 



10^ 



108 



107 



10 6 



2.0 



2.5 



3.0 



3.5 

 1000 

 T°K 



d.O 



4.5 



5.0 



Fig. 7 — The variation of tii with temperature. 



