| 摘要 |
A method for forming contact holes, capable of achieving an increased tolerance in design rule for formation of contact holes by: forming an insulating film over a semiconductor substrate; coating a positive photoresist film over the insulating film; primarily exposing the photoresist film to a light using a first exposure mask having windows adapted to allow portions of the insulating film corresponding to a part of contact holes to be exposed to the light, the part of contact holes having contact holes arranged diagonally to each other; secondarily exposing the photoresist film to the light using a second exposure mask having windows arranged diagonally to each other and not overlapped with those of the first exposure mask; removing the light-exposed portions of the photoresist film to form a photoresist film pattern for exposing portions of the insulating film respectively corresponding to the contact holes; and forming the contact holes using the photoresist film pattern as a mask. Since an approximation effect of contact holes is reduced by virtue of the increase tolerance in design rule for formation of contact holes, it is possible to obtain a more reduced space between adjacent contacts and thereby to form contact holes having a more increased dimension. Accordingly, the process yield can be increased.
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