Patent ID: 8877081

Claim:
An etching method comprising: placing a base layer and a polymer layer formed on the base layer on a mounting table configured as a lower electrode, the polymer layer having a periodic pattern of a first polymer and a second polymer formed by self-assembling the first polymer and the second polymer of a block copolymer that is capable of being self-assembled; etching the polymer layer such that the second polymer is removed and a pattern of the first polymer is formed for subsequently etching the base layer using the pattern of the first polymer as a mask, wherein the etching the polymer layer includes supplying a high frequency power, which is set such that a great amount of ion energy is distributed within a range smaller than ion energy distribution at which an etching yield of the first polymer is generated and larger than or equal to ion energy distribution at which an etching yield of the second polymer is generated by setting the frequency of the high frequency power to be higher than or equal to 60 MHz, to the mounting table, and supplying a predetermined gas, generating plasma from the supplied gas by the high frequency power, and etching the polymer layer using the generated plasma.