Mask-less ultraviolet photolithography based on CMOS-driven micro-pixel light emitting diodes.
We report on an approach to ultraviolet (UV) photolithography and direct writing where both the exposure pattern and dose are determined by a complementary metal oxide semiconductor (CMOS) controlled micro-pixellated light emitting diode array. The 370 nm UV light from a demonstrator 8 x 8 gallium nitride micro-pixel LED is projected onto photoresist covered substrates using two back-to-back microscope objectives, allowing controlled demagnification. In the present setup, the system is capable of delivering up to 8.8 W/cm2 per imaged pixel in circular spots of diameter approximately 8 microm. We show example structures written in positive as well as in negative photoresist.
Elfström
D
D
Institute of Photonics, University of Strathclyde, Glasgow G4 0NW, UK.
Guilhabert
B
B
McKendry
J
J
Poland
S
S
Gong
Z
Z
Massoubre
D
D
Richardson
E
E
Rae
B R
BR
Valentine
G
G
Blanco-Gomez
G
G
Gu
E
E
Cooper
J M
JM
Henderson
R K
RK
Dawson
M D
MD
D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008029:Lighting / Q000295:instrumentation*; D008420:Manufactured Materials / Q000528:radiation effects*; D008904:Miniaturization; D010777:Photochemistry / Q000295:instrumentation*; D010781:Photography / Q000295:instrumentation*; D012666:Semiconductors; D014466:Ultraviolet Rays