SEMICONDUCTOR STRUCTURES AND METHODS FOR MULTI-LEVEL WORK FUNCTION

摘要

A semiconductor structure is provided comprising a vertical channel structure extending from a substrate and formed as a channel between a source region and a drain region. The semiconductor structure further comprises a metal gate that surrounds a portion of the vertical channel structure. The metal gate has a gate length. The metal gate has a first gate section with a first workfunction and a first thickness. The metal gate also has a second gate section with a second workfunction and a second thickness. The first thickness level is different from the second thickness level and the sum of the first thickness level and the second thickness level is equal to the gate length. The ratio of the first thickness level to the second thickness level for the gate length was chosen to achieve a threshold voltage level for the semiconductor device.

主权项

1. A semiconductor structure comprising:
a vertical channel structure extending from a substrate and formed as a channel between a source region and a drain region; and a first metal gate surrounding a portion of the vertical channel structure and having a gate length, the first metal gate having a first gate section with a first workfunction and a first thickness, the first metal gate having a second gate section with a second workfunction and a second thickness, wherein the first thickness is different from the second thickness and the sum of the first thickness and the second thickness is equal to the gate length, and wherein the ratio of the first thickness to the second thickness for the gate length was chosen to achieve a threshold voltage level for the semiconductor device.