Abstract: The present application provides a method for reducing a loss of a dielectric layer in an IO silicon oxide removal process, a plurality of gate structures arranged on a silicon bulk and spaced apart from each other, and an IO silicon oxide layer located between the bottom of the gate structure and the silicon bulk; depositing an etch stop layer; the gate structure being composed of a polysilicon structure, a first hard mask layer, and a second hard mask layer stacked from bottom to top; depositing a first dielectric layer to fill a space between the gate structures; performing etch back of the first dielectric layer; depositing a silicon nitride layer to continuously cover an upper surface of the first dielectric layer and an upper surface of the exposed etch stop layer; depositing a second dielectric layer on the silicon nitride layer.

Abstract: The present invention relates to a new type of oil displacement agent and the process for preparing the same. The oil displacement agent is formed of a polyacrylamide-based polymer characterized by a partly crosslinked and partly branched structure, wherein said polyacrylamide-based polymer is obtained by aqueous copolymerization of acrylamide and N,N-dimethylaminoethyl methacrylate as a functional monomer, in the presence of a redox initiator system.

Abstract: The present invention relates to a new type of oil displacement agent and the process for preparing the same. The oil displacement agent is formed of a polyaclylamide-based polymer characterized by a partly crosslinked and partly branched structure, wherein said polyacrylamide-based polymer is obtained by aqueous copolymerization of acrylamide and N,N-dimethylaminoethyl methacrylate as a functional monomer, in the presence of a redox initiator system.