Patent ID: 9601384
Date: 2017-03-21
CPC Classifications: H01L

Claim:
1. A method of forming a semiconductor device, comprising: forming a plurality of isolation regions on a semiconductor substrate that are laterally spaced from one another by semiconductive material of the semiconductor substrate in a straight line vertical cross section; forming a first stack over a first portion of the semiconductor substrate, the first stack comprising hafnium and metal, the first stack having a first terminating edge that is over one of the spaced isolation regions in the straight line vertical cross section; forming a second stack over a second portion of the semiconductor substrate the second stack comprising hafnium and metal, the second stack having a second terminating edge that is over the one spaced isolation region and is spaced from the first terminating edge in the straight line vertical cross section; forming a conductive layer over the first and second stacks and over the one isolation region between the first and second terminating edges in the straight line vertical cross section; forming a first nitride layer over the conductive layer by using a first deposition method; forming a second nitride layer over the first nitride layer by using a second deposition method different from the first disposition method; and removing a portion of the second nitride layer, a portion of the first nitride layer, a portion of the conductive layer, a portion of the second stack and a portion of the first stack, so as to form a third stack, a fourth stack and a fifth stack, the third stack comprising a material of the first stack, the conductive layer, the first and second nitride layers, the fourth stack comprising a material of the second stack, the conductive layer, the first and second nitride layers, the fifth stack comprising the conductive layer and the first and second nitride layers and placed between the third and fourth stacks over the one isolation region in the straight line vertical cross section.