| 摘要 |
A technique of exposing a resist with electron beams having different accelerating voltages is used in a method for manufacturing a photomask. In a first exposing step, an electron beam resist on a substrate is exposed with an electron beam having an accelerating voltage low enough to keep the electron beam resist from developing. In a second exposing step, the electron beam resist is exposed with an electron beam having a higher accelerating voltage. Through the first and second exposing steps, the electron beam resist absorbs an amount of energy greater than the threshold energy, i.e., enough energy to allow the photoresist to be developed. This technique is applied to a resist coating at least one of an opaque layer and a phase shift film form on a transparent substrate. After the resist is developed, the opaque layer and/or phase shift film is etched using the patterned resist as an etching mask. The technique can also be applied to the forming of test patterns used in producing data by which the dosages of the electron beams used to manufacture the photomask are selected. The use of the two electron beams in exposing the resist facilitates the production of a pattern having a high degree of resolution in a short amount of time.
|
