Importance

Loading Importance Indicators...

Abstract

An improved semiconductor structure and the method for fabricating such is disclosed. The invention relates to the use of thick-oxide for improved field-shield isolation especially as applied to dynamic RAMS's and also to its integration into an improved CMOS process. The improved structure has increased isolation characteristics between adjacent memory cells and still allows for lessened spacing between cells. The corresponding process determines the spacing between cells through etching and eliminates several steps by utilizing one mask for several purposes including defining the active transistor areas and the first polysilicon layer and by extending the use of the first polysilicon layer for field-shield isolation between cells. Additional advantages are disclosed including a higher body effect in the isolation transistors, use of a nitride dielectric layer, and a higher, stable threshold voltage in the isolation transistors. Also, modification of the improved process for fabrication of P-channel and N-channel devices can be made.

Loading the Abstract Image...

First Claim