Etching of Polyimide Using the 9.2-Micron Wavelength of Pulsed CO2 Laser Radiation
Original Publication Date: 1986-Mar-01
Included in the Prior Art Database: 2005-Mar-08
In the manufacture of semiconductor devices polyimide (PI) films are etched to produce holes larger than N 30 mm. This is commonly done by using oxygen plasma or an excimer laser. This article proposes using a CO2 laser for etching which is much simpler and more efficient than the other methods. Several methods have evolved for etching surface relief features into PI. These features range from a couple of microns to over one millimeter in size. Oxygen plasma has a relatively slow etch rate and requires lithographic processing for surface mask definition. The pulsed excimer laser method produces fairly large etch rates and by projection etching is able to eliminate the need for surface masking by lithography.