A method of improving the flatness of a microdisplay surface is disclosed. A reflective mirror layer and a raised layer are formed in order on substrate. The raised layer may comprise a buffer layer and a stop layer, and pixel electrode areas are defined therefrom and gaps are consequently formed among the pixel electrode areas. A dielectric layer is deposited on the pixel electrode areas and fills the gaps. A dielectric layer is partially removed such that the portion on the raised layer is completely removed and the portion filling the gaps are partially removed, thereby the remaining dielectric layer in the gaps has a height not lower than the top of the mirror layer. Thereafter, the raised layer is entirely or partially removed. A transparent conductive layer may be further combined onto the semiconductor substrate and a liquid crystal filling process is performed to form an LCoS display panel.