Open AccessContact photolithography using a carbon-black embedded soft photomask and ultraviolet light emitting diodes with application on patterned sapphire substrates
Author(s) -
Heng Hsieh,
Chun Ying Wu,
Yung-Chun Lee
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.008620
Subject(s) - photomask , photolithography , materials science , optoelectronics , polydimethylsiloxane , ultraviolet , light emitting diode , sapphire , optics , diode , lithography , extreme ultraviolet lithography , soft lithography , fabrication , laser , nanotechnology , resist , layer (electronics) , medicine , physics , alternative medicine , pathology
This paper presents a contact photolithography method for large-area ultraviolet (UV) patterning using a soft polydimethylsiloxane (PDMS) photomask and a planar light source consisting of arrayed light-emitting diodes (LEDs). With simple design and construction, the UV light source can achieve uniformly distributed UV light intensity over an area of 4" in diameter but its divergent angle is 15°. To overcome this large divergent angle, a PDMS soft mold embedded with carbon-black inserts as the UV light blocking materials is applied. It is demonstrated that, when increasing the aspect ratio of the carbon-black inserts, one can achieve excellent UV patterning results. Both experimental data and simulation results are presented. This contact photolithography system has been successfully used for manufacturing patterned sapphire substrates (PSSs) in LED industry. The advantages and potential applications of the proposed method will be addresses.