Patent ID: 7884020

Claim:
A method of manufacturing a semiconductor device, comprising: forming a trench on a semiconductor substrate; forming an insulating film on the semiconductor substrate having the trench formed thereon; and forming a buried element isolating region by supplying a polishing slurry containing abrasive grains onto the surface of a polishing cloth which comprises a molded body of a (meth)acrylic copolymer having an acid value of 10 to 100 mg KOH/g and a hydroxyl group value of 50 to 150 mg KOH/g, while rotating the semiconductor substrate under the state that the insulating film formed on the semiconductor substrate is allowed to abut against the polishing cloth, thereby polishing the upper portion of the insulating film such that the lower portion of the insulating film is left unremoved inside the trench, the unremoved lower portion of the insulating film forming the buried element isolating region, wherein the (meth)acrylic copolymer is represented by general formula (I) given below, in which the atomic group generating the acid value is formed of a constituting unit based on the (meth)acrylic acid, and the atomic group generating the hydroxyl group value is formed of a constituting unit based on the (meth)acrylic acid hydroxyalkyl ester: where R1, R2 and R3 independently denote a hydrogen atom or a methyl group, R4 denotes a linear or branched alkylene group having 2 to 4 carbon atoms, R5 denotes a linear or branched alkyl group having 1 to 18 carbon atoms, and each of l, m and n denotes the amount (% by weight) of the constituting unit based on each monomer, the values of l, m and n being chosen to permit the copolymer to exhibit an acid value of 10 to 100 mg KOH/g and a hydroxyl group value of 50 to 150 mg KOH/g.