Voltage-controlled bidirectional switch

Abstract

A voltage-controlled vertical bidirectional monolithic switch, referenced with respect to the rear surface of the switch, formed from a lightly-doped N-type semiconductor substrate, in which the control structure includes, on the front surface side, a first P-type well in which is formed an N-type region, and a second P-type well in which is formed a MOS transistor, the first P-type well and the gate of the MOS transistor being connected to a control terminal, said N-type region being connected to a main terminal of the MOS transistor, and the second main terminal of the MOS transistor being connected to the rear surface voltage of the switch.

1 . A voltage-controlled vertical bidirectional monolithic switch, referenced with respect to a rear surface of the switch, formed from a lightly-doped N-type semiconductor substrate, wherein a control structure comprises, on a front surface side, a first P-type well in which is formed an N-type region, and a second P-type well in which is formed a MOS transistor, the first P-type well and the gate of the MOS transistor being connected to a control terminal, said N-type region being connected to a main terminal of the MOS transistor, and the second main terminal of the MOS transistor being connected to the rear surface voltage of the switch. 
   
   
       2 . The switch of  claim 1 , wherein the monolithic structure is surrounded with a heavily-doped P-type wall in contact with a rear surface metallization, the connection between the second main terminal of the MOS transistor and the voltage of the rear surface being ensured by a metallization connecting this second main terminal to the upper surface of said wall. 
   
   
       3 . The switch of  claim 1 , wherein the connection between the control terminal and, on the one hand, the first P-type well and, on the other hand, the gate is ensured via respective resistors, the first resistance between the control terminal and a contact on the first well being high and the second resistance between the control terminal and the gate being low. 
   
   
       4 . The switch of  claim 3 , wherein the first resistance is on the order of some hundred kilo-ohms and the second resistance is smaller than 100 ohms. 
   
   
       5 . The switch of  claim 1 , comprising, on the rear surface side, between the semiconductor structure and the rear surface metallization, an insulating layer extending at least under the control area and not under the power area.