Patent ID: 6602807
Filing Date: 2003-08-05
Classification: H01L

Abstract:
A method of forming a semiconductor device, the method comprising the steps of:providing a silicon-comprising substrate having a surface comprising at least one first wordline comprising P-type silicon and at least one second wordline comprising N-type silicon, the first and second wordlines being separated on the substrate; contacting the substrate with ozone and tetraethylorthosilicate, wherein delivery of the ozone is pulsed on and off, and delivery of the ozone and the tetraethylorthosilicate is via a linear injector, whereby the first wordline and the second wordline are in intimate contact with the ozone and the tetraethylorthosilicate; reacting the ozone and the tetraethylorthosilicate to selectively deposit silicon oxide over the substrate surface and both the first wordline and the second wordline, whereby a greater thickness of silicon oxide is deposited on the first wordline than on the second wordline; and, etching the silicon oxide deposited on the substrate to remove silicon oxide from the surface of the substrate, whereby the silicon oxide layers remaining on the first and second wordlines provides a layer of variable thickness around the first wordline and the second wordline; wherein the semiconductor device is a memory array having wordlines with spacers of variable thickness.