Control of edge bulge evolution during photoresist reflow and it's application to diamond micro-lens fabrication

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

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.
LanguageEnglish
Article number021602
Number of pages6
JournalJournal of Vacuum Science and Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena
Volume34
Issue number2
DOIs
Publication statusPublished - 9 Mar 2016

Fingerprint

Diamond
Photoresists
photoresists
Lenses
Diamonds
diamonds
lenses
Fabrication
fabrication
curvature
radii
Plasma etching
Inductively coupled plasma
plasma etching
profiles
selectivity
Temperature
temperature
propagation

Keywords

  • photoresist patterns
  • thermal reflow
  • diamond micro-lens
  • micro-lens fabrication

Cite this

@article{07640c10a61d45f287b73948799ed130,
title = "Control of edge bulge evolution during photoresist reflow and it's application to diamond micro-lens fabrication",
abstract = "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.",
keywords = "photoresist patterns, thermal reflow, diamond micro-lens, micro-lens fabrication",
author = "Hangyu Liu and Johannes Herrnsdorf and Erdan Gu and Dawson, {Martin D.}",
note = "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.",
year = "2016",
month = "3",
day = "9",
doi = "10.1116/1.4943558",
language = "English",
volume = "34",
journal = "Journal of Vacuum Science and Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena",
issn = "2166-2746",
number = "2",

}

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

VL - 34

JO - Journal of Vacuum Science and Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena

T2 - 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

SN - 2166-2746

IS - 2

M1 - 021602

ER -