Semiconductor device, semiconductor element and method for producing same

Abstract

A semiconductor device comprises: a semiconductor substrate; a plurality of first diffusion layers having a low impurity density, the first diffusion layers being formed on the surface of the semiconductor substrate; a plurality of second diffusion layers having a high impurity density, the second diffusion layers being formed on the surface of the semiconductor substrate; a plurality of first contacts, each of which contacts the first diffusion layers and each of which is formed of a semiconductor; and a plurality of second contacts, each of which contacts the second diffusion layers and each of which is formed of a metal.

1 . A semiconductor device comprising: 
 a plurality of memory transistors each having a floating gate and a control gate, said memory transistors arranged in column direction being connected to each other in series to form a transistor unit, and one end of the transistor unit being a drain side terminal and the other end of the transistor unit being a source side terminal; and    at least one select gate transistor functioning as a gate for transmitting and receiving data, said select gate transistor connecting said drain side terminal with a bit line or connecting said source side terminal with a source line, a select gate electrode of the select gate transistor being connected to a transistor select line via a gate electrode contact made of polysilicon, a column direction width of the gate electrode contact being wider than a column direction width of the select gate transistor in a plane involving an upper surface of the select gate electrode.    
   
   
       2 . The semiconductor device according to  claim 1 , wherein the select gate transistor is connected with the bit line or the source line via a bit line contact or a source line contact each made of polysilicon.  
   
   
       3 . The semiconductor device according to  claim 2 , wherein the polysilicon of the gate electrode contact and the polysilicon of the bit line contact or the source line contact are the same polysilicon.  
   
   
       4 . The semiconductor device according to  claim 3 , wherein the material of the select gate electrode and the material of the floating gate are the same material.