Method for improving height difference of grids with different sizes

• Main Authors: PENG XIANG, CHENG QI, GUO YANGKUN
• Format: Patent
• Language: Chinese; English
• Published: 17.05.2024
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The invention provides a method for improving the height difference of grids with different sizes, which comprises the following steps of: providing a substrate which comprises a short channel device region and a long channel device region, forming a grid dielectric layer and a first pseudo grid polycrystalline silicon layer and a second pseudo grid polycrystalline silicon layer on the grid dielectric layer on the short channel device region and the long channel device region, the width of the first pseudo gate polycrystalline silicon layer is smaller than that of the second pseudo gate polycrystalline silicon layer, and side wall structures are formed on the side walls of the first pseudo gate polycrystalline silicon layer and the second pseudo gate polycrystalline silicon layer; forming an etching stop layer covering the first pseudo gate polycrystalline silicon layer, the second pseudo gate polycrystalline silicon layer and the side wall structure on the substrate, and forming an interlayer dielectric laye