TY - JOUR
T1 - Control of edge bulge evolution during photoresist reflow and it's application to diamond micro-lens fabrication
AU - Liu, Hangyu
AU - Herrnsdorf, Johannes
AU - Gu, Erdan
AU - Dawson, Martin D.
N1 - The following article has been accepted by Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics. After it is published, it will be found at http://scitation.aip.org/content/avs/journal/jvstb.
PY - 2016/3/9
Y1 - 2016/3/9
N2 - We present an empirical study of profile evolution of lithographically defined photoresist (PR) patterns during thermal reflow and apply the findings to diamond micro-lens fabrication. During PR reflow, a bulge forms at the edge of the PR pattern and propagates inwards as the temperature and PR thickness are increased. An empirical relationship for this propagation is derived. Furthermore, it was found that at a certain reflow temperature and a limited pattern size, there is a minimum initial thickness of the PR pattern for forming spherical lens profiles. Based on these findings, diamond micro-lenses with a diameter of 400 µm and a previously unachieved radius of curvature of over 13 mm were fabricated. This is underpinned by forming PR micro-lens patterns with a large radius of curvature and transferring the PR patterns through low-selectivity Ar/Cl2 inductively coupled plasma etching.
AB - We present an empirical study of profile evolution of lithographically defined photoresist (PR) patterns during thermal reflow and apply the findings to diamond micro-lens fabrication. During PR reflow, a bulge forms at the edge of the PR pattern and propagates inwards as the temperature and PR thickness are increased. An empirical relationship for this propagation is derived. Furthermore, it was found that at a certain reflow temperature and a limited pattern size, there is a minimum initial thickness of the PR pattern for forming spherical lens profiles. Based on these findings, diamond micro-lenses with a diameter of 400 µm and a previously unachieved radius of curvature of over 13 mm were fabricated. This is underpinned by forming PR micro-lens patterns with a large radius of curvature and transferring the PR patterns through low-selectivity Ar/Cl2 inductively coupled plasma etching.
KW - photoresist patterns
KW - thermal reflow
KW - diamond micro-lens
KW - micro-lens fabrication
UR - http://scitation.aip.org/content/avs/journal/jvstb
U2 - 10.1116/1.4943558
DO - 10.1116/1.4943558
M3 - Article
SN - 2166-2746
VL - 34
JO - Journal of Vacuum Science and Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena
JF - Journal of Vacuum Science and Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena
IS - 2
M1 - 021602
ER -