| 摘要 |
PURPOSE: A method of forming a contact is to increase size of an opening portion on a contact hole, thereby improving a step coverage in a subsequent metal deposition process and implementing a low-resistant metal contact. CONSTITUTION: The first BPSG(borophosphosilicate glass) layer(180,220,280) is deposited on a semiconductor substrate(100) including a contact area and is reflowed to planarize an upper surface thereof. The second BPSG layer(260) is then deposited on the planarized first BPSG layer. The second BPSG layer and the planarized first BPSG layer are anisotropically etched to form a contact hole(280) exposing the contact area. As the second BPSG layer has not been reflowed at a high temperature, it has a higher etch rate compared to that of the first BPSG layer, thus developing a profile having a widened contact opening.
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