| 摘要 |
<p>PURPOSE:To obtain an enough phase shift effect and to stabilize production process and quality by dry etching the phase shifter part to half way of the required depth and then removing the shifter part to the required thickness by wet etching. CONSTITUTION:First, a tantalum is formed as an etcing stopper layer 2 on a transparent substrate 1 and then a SiO2 film as a phase shifter layer 3 is formed thereon. This SiO2 film is etched to half way of the required depth by dry etching. Thus, a perpendicular cross section having high etching anisotropy can be obtd. which enables easy control of line width. After this, by wet etching the film, a protective film generating as a side wall of the cut edge and the residual matter are removed. By using wet etching, isotropic etching is also effected to etch the film in the horizontal direction. Thus, edges of the shifter layer 3 is formed inside of the light shielding pattern 4 and thereby, scattering of light transmitting through side walls can be prevented.</p> |
