| 摘要 |
本案系关于一种于金氧半场效电晶体形成遮蔽闸之方法，包括步骤：提供具有至少一沟渠之一半导体基板；于该半导体基板之该沟渠内形成一底层闸氧化物区及一遮蔽闸多晶矽区；以高温度电浆沉积、多晶矽回蚀及氧化物回蚀于该遮蔽闸多晶矽区上形成一多晶矽间氧化物区；以及于该多晶矽间氧化物区上形成一闸氧化物区及一闸多晶矽区。藉由使用回蚀制程取代传统化学机械研磨制程，可使制造遮蔽闸结构之制造成本降低，进而达到降低场效电晶体总成本之功效。同时，遮蔽闸结构可有效降低场效电晶体之闸电荷，以达到提升场效电晶体整体表现之功效。;A method for forming a shielded gate of a MOSFET includes steps as following: providing a semiconductor substrate having at least one trench, forming a bottom gate oxide region and a shielded gate poly region in the trench of the semiconductor substrate, forming an inter-poly oxide region on the shielded gate poly region through high temperature plasma deposition, poly etching back and oxide etching back; and forming a gate oxide region and a gate poly region on the inter-poly oxide region.By utilizing the etching back processes in replace of traditional chemical mechanical polishing processes, the fabricating cost of fabricating a shielded gate structure is reduced, and the total cost of manufacturing a FET is also reduced.Meanwhile, the gate charge is effectively reduced due to the shielded gate structure, so that the performance of a MOSFET is enhanced. |
