METHOD FOR FABRICATING INTERLAYER DIELECTRIC IN SEMICONDUCTOR DEVICE

摘要

A method for forming an interlayer dielectric in a semiconductor device is provided to prevent damage of a hard mask layer of a gate stack and reduction of a threshold voltage by performing a reflow process using a nitrogen monoxide(N2O) to remove voids. A gate pattern(240) is formed on a semiconductor substrate(200) where a cell region(A) and a peripheral circuit region(B) are formed. A buffer oxide layer(250), a spacer nitride layer(260), and a spacer oxide layer(270) are formed on the whole surface of the semiconductor substrate including the gate pattern. A first mask layer pattern opening the peripheral circuit region is formed. A spacer layer is formed on the peripheral circuit region by using the first mask layer pattern as a mask. A second mask layer pattern is formed to open the cell region. The spacer oxide layer of the cell region is removed by using the second mask layer pattern as a mask. A dielectric(310) is formed on a gate stack of the cell region and the second mask layer pattern is removed. An interlayer dielectric layer is formed on the semiconductor substrate. Thermal process is performed on the semiconductor substrate at N2O atmosphere to planarize the interlayer dielectric.