| 摘要 |
<p>PURPOSE:To augment the overlap precision of a transfer mask by a method wherein the title transfer mask is formed of the marks serving both as exposure alignment marks and electron beam lithographic reference marks and then a circuit pattern is formed on a substrate surface using the transfer mask. CONSTITUTION:A pattern is successively transferred to lower layers by multilayer dry-etching step to form a multilayer structured mask pattern 9 on a W film 3 and then the W film 3 is dry-etched away by reactive ion etching step to form the marks 10 serving both as electron beam lithographic reference marks comprising W and exposure alignment marks. Next, after ashing a specimen with oxygen plasma, heat-treated resist 11, and a TiSi layer 12 are formed as lower layers and a negative type electron beam resist 13 as the topmost layer and then the marks 10 serving both as the electron beam lithographic reference marks and exposure alignment marks are used as the lithographic alignment reference in the electron beam lithographic step so as to form a specific circuit pattern. Through these procedures, the overlap precision in semiconductor lithographic step can be augmented.</p> |
