Microlenses and photodetectors integration for augmenting photocurrent

Author

Gomes, Johnny Moreira ; Rocha, Rui P. ; Correia, J.H. ; Carmo, J.P.

Author_Institution

Dept. of Ind. Electron., Univ. of Minho, Guimaraes, Portugal

fYear

2014

fDate

1-5 Sept. 2014

Firstpage

1

Lastpage

5

Abstract

This paper presents two approaches in microlenses (MLs) and photodiodes (PDs) integration for improving the light-photocurrent conversion. The first one consists in fabricating MLs with AZ4562 photoresist on a glass substrate: The integration of MLs with a focal length of 170 μm on a 150 μm thickness glass substrate aligned on top of a 240 μm square CMOS photodiode resulted in a decrease of ≈38% for the light-current conversion under white light. In the second approach the MLs were fabricated also with AZ4562 in 24-5 μm width-thickness (at the apex) on top of a 240 μm and 24 μm square CMOS photodiodes. The results showed an increase in light-current conversion in both cases: The 240 μm photodiode presented an increase of ≈2.6% and ≈5.2% under white and red light respectively, while the 24 μm photodiode presented an increase of ≈2.3% and ≈14.5% also under white and red light respectively.

Keywords

CMOS integrated circuits; microlenses; optical fabrication; photoconductivity; photodetectors; photodiodes; photoresists; AZ4562 photoresist; CMOS; glass substrate; light-current conversion; light-photocurrent conversion; microlenses; photodetectors; photodiode; size 150 mum; size 170 mum; size 24 mum to 5 mum; size 240 mum; CMOS integrated circuits; Optical device fabrication; Optical sensors; Optical variables measurement; Photodiodes; Substrates; Voltage measurement; image sensor; light-current; microlenses; photocurrent; photodiodes;

fLanguage

English

Publisher

ieee

Conference_Titel

Microelectronics Technology and Devices (SBMicro), 2014 29th Symposium on

Conference_Location

Aracaju

Type

conf

DOI

10.1109/SBMicro.2014.6940110

Filename

6940110