发明名称 |
Method for forming a void-free tungsten-plug contact in the presence of a contact opening overhang |
摘要 |
A method for the fabrication of an ohmic, low resistance contact to silicon is described using a CVD deposited tungsten plug provided with Ti/TiN barrier metallurgy. The method provides for a glass insulator layer deposited on the silicon. After the glass is flowed to planarize its surface, contact holes are patterned in the glass exposing the silicon substrate. The Ti/TiN barrier metallurgy is deposited by sputtering which, because of inferior edge coverage, results in a sidewall with a negative taper. Subsequent deposition of the tungsten results in a tungsten plug with an exposed void. The method taught by this invention deposits first a thin layer of tungsten whose thickness is governed by the amount of overhang caused by the tapered sidewall. An anisotropic dry etch step is then performed to achieve a vertical sidewall of tungsten. The remaining tungsten is then deposited to fill the contact opening without the occurrence of voids.
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申请公布号 |
US5654234(A) |
申请公布日期 |
1997.08.05 |
申请号 |
US19960638674 |
申请日期 |
1996.04.29 |
申请人 |
TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD. |
发明人 |
SHIH, TSU;YU, CHEN-HUA DOUGLAS |
分类号 |
H01L21/285;(IPC1-7):H01L21/283 |
主分类号 |
H01L21/285 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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