Patent ID: 9548228
Date: 2017-01-17
CPC Classifications: H01L

Claim:
1. A method of processing semiconductor substrates, comprising: (i) providing a substrate comprising features having different size openings including a first feature and a second feature, wherein the first feature is separated and space apart from the second feature, wherein the first feature has a smaller opening than the second feature; (ii) depositing a first bulk tungsten layer in the features to partially fill the features; (iii) performing a nonconformal etch of the first bulk tungsten layer to leave an etched tungsten layer in the features, including removing more tungsten from the top of the first feature than in the interior of the first feature; (iv) depositing a second bulk tungsten layer on the etched tungsten layer; and (v) after the first feature is completely filled with tungsten and before the second feature is completely filled with tungsten, treating a surface of the second bulk tungsten layer.