| 摘要 |
PURPOSE: To prevent the residue of a photoresist in a viahole and to improve the yield of an interlayer connection by increasing the exposure diameter of the viahole larger than the design diameter of the viahole. CONSTITUTION: After a first layer wiring is obtained, a negative type inter layer insulating film 7 is formed. After the pattern of a viahole is exposed, it is developed to form viaholes 8a-8d. Thereafter, a second layer base conductor film 3b is formed, a positive type photoresist layer is formed thereon, a viahole having a design diameter X and a second layer wiring pattern are exposed, the viaholes 8a-8d are further exposed by using a positive type photomask 5d having larger exposure diameter Z than the diameter X, and developed to obtain a second layer wiring pattern. Then, after a second layer conductor 6b is formed, the part not formed with the conductor 6b of the photoresist 4 and the base conductor film 3b is removed to obtain a two-layer circuit board. |
