| 摘要 |
A phase shifting lithographic process capable of creating a shrunk fine line pattern on a photoresist layer coated on a semiconductor wafer is disclosed. A first phase shift mask is prepared, which comprises thereon a first phase shift clear area, a second phase shift clear area situated adjacent to the first phase shift clear area, a vertical control chrome line section disposed at a boundary between the first phase shift clear area and the second phase shift clear area, and a horizontal opaque area connected to the vertical control chrome line section in an orthogonal manner. A first exposure process is implemented to expose the photoresist layer to light transmitted from clear areas of the first phase shift mask so as to form a vertical fine line image corresponding to the vertical control chrome line section disposed at a boundary between the first phase shift clear area and the second phase shift clear area, a horizontal unexposed area connected to the vertical fine line image in an orthogonal manner, and a peripheral unexposed line pattern. A second phase shift mask is prepared, which comprises thereon a third phase shift clear area, a fourth phase shift clear area situated adjacent to the third phase shift clear area, a horizontal control chrome line section disposed at a boundary between the third phase shift clear area and the fourth phase shift clear area, and a vertical opaque area connected to the horizontal control chrome line section in an orthogonal manner for shielding the vertical fine line image on the photoresist layer. A second exposure process is implemented to expose the photoresist layer to light transmitted from clear areas of the second phase shift mask so as to form a horizontal fine line image corresponding to the horizontal control chrome line section disposed at a boundary between the third phase shift clear area and the fourth phase shift clear area.
|
