| 摘要 |
PURPOSE: A contact formation method in semiconductor devices is provided to be capable of securing a vertical contact cross-section having a select ratio higher than a nitride film and of securing a low contact resistance. CONSTITUTION: A contact formation method includes the following steps. A field oxide film(22) and a word line is first formed on a semiconductor substrate(21). After depositing a nitride film on the entire structure, a nitride film spacer(24) is formed by etch process. Then, an oxide film for protecting the silicon substrate and a pad poly are sequentially deposited on the entire structure. Next, an interlayer insulating oxide film(29) is deposited on the entire structure with only the contact pad left by the pad poly etch process using a contact pad mask. After forming an oxide film, a contact mask(30) is formed on the insulating oxide film. Thereafter, the exposed insulating oxide film is etched to expose the contact pad. After removing the exposed contact pad by dry etch, the oxide film for protecting the silicon substrate.
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