钨化学气相淀积工艺方块电阻均匀性的研究

Study of the Sheet Resistance Uniformity in the Tungsten Chemical Vapor Deposition

钨化学气相淀积因为其在接触孔/通孔填充中出色的台阶覆盖能力而在半导体工业中被广泛应用,在量产中经常会出现监控片的方块电阻均匀性超规格。本文主要研究了加热器、气体输送、氟化铝、机械传片定位、真空微漏等因素对方块电阻均匀性的影响,特别周期性等离子清洗产生的氟化铝对晶圆边缘的抑制反应是影响腔体维护频率的主要原因,并提出改善均匀性的有效办法。

Tungsten chemical vapor deposition is used widely as contact/via plug because of excellent step coverage in semiconductor industry, but the tool encounters frequently the sheet resistance uniformity out of control in daily monitor wafer during mass production. The paper studied the variable factors which affect the sheet resistance uniformity such as heater, gas transfer, aluminum fluoride, mechanical positioning, and vacuum leakage. Especially aluminum fluoride originated from periodic plasma clean inhibits the reaction at wafer edge and shortens the preventive maintenance of process chamber. The papers also proposed some methods to improve uniformity.