Abstracts Book - IMRC 2018

• SF2-P011
A METHOD TO CONFIGURE A STANDARD MARKING LASER AS A
LOW-COST PATTERN GENERATOR TO OBTAIN PHOTOMASKS FOR
FABRICATION OF ELECTRONIC DEVICES
Norberto Hernandez Como 1 , Miguel Angel Lopez Castillo 2 , Francisco Javier Hernandez Cuevas 1 ,
Hector Baez Medina 3 , Marco Ramirez Salinas 3 , Miguel Angel Aleman 1
1 Instituto Politécnico Nacional - IPN, Centro de Nanociencias y Micro y Nanotecnologías,
Mexico. 2 Instituto Politécnico Nacional - IPN, Escuela Superior de Ingeniería Química e
Industrias Extractivas, Mexico. 3 Instituto Politécnico Nacional - IPN, Centro de Investigación en
Computación, Mexico.
The photomasks are very useful for the mass production of electronic devices
and integrated circuits with resolution of up to 0.6 um using optical lithography.
Photomasks are normally comprised of a glass substrate (~1-3 mm), followed by
a chrome film (~100 nm) and on top of these two a positive photoresist (~500
nm). Custom circuit designs are normally transferred onto the photomask using
pattern generators (mask writer) with a 405 nm laser. In this work, we configured
a SISMA Big Smarky 200F 20 W marking laser (Yb 1064 nm) as a pattern
generator to produce photomasks with a resolution of up to 10 um. The effect
of the marking laser parameters such as speed, frequency, power and filling
space is discussed in order to produce high quality patterns. Our results indicate
that the photoresist is hardened when exposed to the marking laser, and the
unexposed photoresist is removed during the developing. A power of 8% is
crucial to achieve this annealing effect only on the photoresist and to avoid
permanent damaging on the chrome film and the glass. This produces a result
contrary to the common mask writer equipment where the photoresist exposed
to the 405 nm laser is removed in the developer. Our method can be used to
configure any commercial marking laser into a pattern generator which prices
are normally 1/3 up to 1/5 of commercial pattern generators. The proposed
method is helpful for design testing and fast prototyping of electronic devices.
Acknowledgment:
This work was supported by CONACYT-Mexico under grant CB-2014/240103 and
by SIP-IPN under grant 20180533.
Keywords: pattern generator, photolitography, electronic devices
Presenting authors email: nohernandezc@ipn.mx