Wh. Bruenger et al., HPR-506 PHOTORESIST USED AS A POSITIVE TONE ION RESIST, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 14(6), 1996, pp. 3924-3927
A positive tone photo resist HPR 506 (Olin Microelectronic Materials)
has been investigated for its performance under ion exposure. Experime
nts have been conducted with light ions (H+ and He+) in the ion projec
tor IPLM 02 (IMS; Vienna) at an energy of 75 keV. The resist resolutio
n proved to be similar to 180 nm which is not as good as the projector
resolution of below 80 nm as demonstrated with Polymethylmetacrylate.
The sensitivity of HPR 506 resist in positive tone amounts to 1.2 x 1
0(13) H+ ions/cm(2) and 6 x 10(12) He+ ions/cm(2) with contrast number
s of 3.3 and 3.2, respectively. The dose gap between positive and nega
tive mode is sufficiently high (factor of 3) to guarantee a good proce
ss stability. The exposure latitude for He+ exposure has a value of 15
nm. The sensitivity does not oscillate with resist thickness like in
optical lithography. These performance data confirm that HPR 506 resis
t can be used for mix and match exposure in ion projectors and i-line
steppers. (C) 1996 American Vacuum Society.