I checked the IBM Patent Server for patents by Blum and/or Srinivasan. They have lots of patents in the laser area, but I did not see any that are directly applicable to CYMI. Be forewarned, I used the titles as a guide, and did not check all of their patents in detail.
They have a number of patents for ablating ("blowing away") the photoresist in patents 4,414,059; 4,417,948; and 4,568,632. This process does not require a development step, and it is different from traditional photolithography. They also have a patent on using an ArF laser for dentistry or surgery -- 4,784,135. Here's an example of one of the ablation patents:
4414059 : Far UV patterning of resist materials
INVENTORS:
Blum; Samuel E., White Plains, NY
Brown; Karen H., Yorktown Heights, NY
Srinivasan; Rangaswamy, Ossining, NY
ASSIGNEES:
International Business Machines Corporation, Armonk, NY
Contact the IBM Licensing Department for information about this patent
ISSUED:
Nov. 8 , 1983
FILED:
Dec. 9 , 1982
SERIAL NUMBER:
448126
ABSTRACT: A technique is described for the fabrication of devices and circuits using multiple layers of materials, where
patterned layers of resists are required to make the device or circuit. The fabrication process is characterized by the selective
removal of portions of the resist layer by ablative photodecomposition. This decomposition is caused by the incidence of
ultraviolet radiation of wavelengths less than 220 nm, and power densities sufficient to cause fragmentation of resist polymer
chains and the immediate escape of the fragmented portions from the resist layer. Energy fluences in excess of 10 mJ/cm2
/pulse are typically required. The deliverance of a large amount of energy in this wavelength range to the resist layer in a
sufficiently short amount of time causes ablation of the polymer chain fragments. No subsequent development step is required
for patterning the resist layer.
EXEMPLARY CLAIM(s):
Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:
1. In a thin film fabrication process for producing a device or circuit, the steps as follows:
providing a substrate including at least one layer therein,
depositing a resist layer on said substrate,
removing selected areas of said resist layer by irradiation of said selected areas with ultraviolet light of
wavelengths less than 220 nm and having a sufficient power density to produce ablative photodecomposition of
said irradiated areas to expose portions of said substrate, and
causing a change to said exposed portions of said substrate through said patterned resist layer. |
