JPS6425416A - Electron beam exposure method - Google Patents

Abstract

PURPOSE:To suppress the influence of electrons of an electron beam reflected from a substrate and form a dense, fine pattern where no proximity effect is recognized by preparing a resist having a sensitivity which is inferior to that of an upper layer resist at a lower layer, thereby making the resist have a two-layer resist structure; namely lower and upper layer resists. CONSTITUTION:Lower and upper layer resists 2 and 3 are coated on a silicon substrate 1. It is preferable for the lower layer resist to have sensitivity that is inferior to that of the upper layer resist. Once the resist is irradiated by an electron beam, the upper layer resist is sufficiently exposed to the electron beam but the lower resist is not exposed to its beam. Then the electron beam is reflected to the silicon substrate and even the lower resist is also exposed to its beam. Being different from the case of a single layer resist 3 the arrangement of another resist 2 having inferior sensitivity makes the influence of reflected electrons small. The resultant cross section obtained after its development exhibits a large undercut in the case of the single layer resist as shown by dotted lines 5 but a small undercut in the case of the two-layer resist as shown by solid lines 6.