| 摘要 |
PURPOSE: A formation method of contact holes is provided to prevent a contact top CD(Critical Dimension) widening by selectively etching an anti-reflection layer and an interlayer dielectric after forming a polymer layer as an etch stopper. CONSTITUTION: After sequentially forming a number of word lines(32), a nitride(33), the first BPSG(Boron Phosphor Silicate Glass)(34), and a plug(36) on a semiconductor substrate(31), the plug(36), the first BPSG(34), and the nitride(33) are planarized by a CMP(Chemical Mechanical Polishing) using the word lines(32) as etch ending points. Then, the second BPSG(37), an anti-reflection layer(38), the second photoresist pattern(39), and a polymer layer(40) are sequentially formed on the resultant structure. Then the anti-reflection layer(38) is etched using the second photoresist pattern(39) as a mask. At this time, the polymer layer(40) prevents a top CD widening on the second photoresist pattern(39), thereby restraining a contact top CD widening.
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