摘要 |
A method for creating a metal filled, high aspect ratio, contact opening, in thick insulator layers, allowing contact between a metal interconnect structure and a region of a semiconductor substrate, has been developed. The process features creating a stacked contact hole opening, comprised of a upper contact hole opening, of a specific diameter size, overlying a lower contact hole opening, having an opening larger in diameter than the opening used for the upper contact hole opening. The lower contact hole opening is created via an anisotropic RIE procedure, followed by a wet etch procedure, used to enlarge the diameter of the lower contact hole opening. The upper contact hole opening, created using an anisotropic RIE procedure, is formed using the original diameter opening, used previously for the pre-wet etched, lower contact hole opening, and is easily aligned to a metal filled, enlarged lower contact hole opening.
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