Creating precise 3D microstructures using laser direct-write bimetallic thermal resist grayscale photomasks Export

@inproceedings{citeulike:3874924, abstract = {Previous research demonstrated Sn/In and Bi/In bimetallic thermal resists are promising new materials for direct-write analogue grayscale photomask processes. These materials turn transparent with increased laser exposure power and their optical density changes smoothly from 3 OD when unexposed to less than 0.22 OD when fully exposed. The transparency is the result of an oxidation process that is controllable with exposure to generate the grayscale levels in the photomask. In order to produce precise 3D structures in regular photoresists, the steps involved in microlithography must be quantified and examined. The lithographic process includes drawing 8-bit grayscale bitmap patterns, computer-aided laser writing photomasks on bimetallic films, and regular photoresist exposure using a mask-aligner. Compensation during the mask-writing process was necessary since the relationship between the optical density of the exposed bimetallic films and the laser writing power was not completely linear. In addition, the response of the photoresists to the mask exposure time was also a non-linear relationship. To investigate the resolution limit for Bi/In and Sn/In bimetallic thermal resists as a masking material, we used a modified form of interference lithography to expose and develop structures in Bi/In resists with widths that are less than 200 nm. As a result of the lithography, we were able to create structures in the Bi/In films that are up to 20 times smaller than previously obtained using the direct-write method.}, author = {Chapman, Glenn H. and Dykes, James and Poon, David and Choo, Chinheng and Wang, Jun and Peng, Jun and Tu, Yuqiang}, citeulike-article-id = {3874924}, citeulike-linkout-0 = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PSISDG005713000001000247000001&idtype=cvips&gifs=yes}, citeulike-linkout-1 = {http://link.aip.org/link/?PSI/5713/247}, editor = {Fieret, Jim and Herman, Peter R. and Okada, Tatsuo and Arnold, Craig B. and Bachmann, Friedrich G. and Hoving, Willem and Washio, Kunihiko and Lu, Yongfeng and Geohegan, David B. and Trager, Frank and Dubowski, Jan J.}, journal = {Photon Processing in Microelectronics and Photonics IV}, keywords = {3-d, bimetallic, citedby1, grayscale, lasers, lithography, masks, metallic, microstructures, photoresist, resist, thermal}, location = {San Jose, CA, USA}, number = {1}, pages = {247--258}, posted-at = {2009-01-12 04:47:47}, priority = {2}, publisher = {SPIE}, title = {Creating precise 3D microstructures using laser direct-write bimetallic thermal resist grayscale photomasks}, url = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PSISDG005713000001000247000001&idtype=cvips&gifs=yes}, volume = {5713}, year = {2005} }

TY - CONF ID - citeulike:3874924 L3 - citeulike-article-id:3874924 N2 - Previous research demonstrated Sn/In and Bi/In bimetallic thermal resists are promising new materials for direct-write analogue grayscale photomask processes. These materials turn transparent with increased laser exposure power and their optical density changes smoothly from 3 OD when unexposed to less than 0.22 OD when fully exposed. The transparency is the result of an oxidation process that is controllable with exposure to generate the grayscale levels in the photomask. In order to produce precise 3D structures in regular photoresists, the steps involved in microlithography must be quantified and examined. The lithographic process includes drawing 8-bit grayscale bitmap patterns, computer-aided laser writing photomasks on bimetallic films, and regular photoresist exposure using a mask-aligner. Compensation during the mask-writing process was necessary since the relationship between the optical density of the exposed bimetallic films and the laser writing power was not completely linear. In addition, the response of the photoresists to the mask exposure time was also a non-linear relationship. To investigate the resolution limit for Bi/In and Sn/In bimetallic thermal resists as a masking material, we used a modified form of interference lithography to expose and develop structures in Bi/In resists with widths that are less than 200 nm. As a result of the lithography, we were able to create structures in the Bi/In films that are up to 20 times smaller than previously obtained using the direct-write method. CY - San Jose, CA, USA IS - 1 JF - Photon Processing in Microelectronics and Photonics IV EP - 258 TI - Creating precise 3D microstructures using laser direct-write bimetallic thermal resist grayscale photomasks PB - SPIE VL - 5713 SP - 247 KW - 3-d KW - bimetallic KW - citedby1 KW - grayscale KW - lasers KW - lithography KW - masks KW - metallic KW - microstructures KW - photoresist KW - resist KW - thermal AU - Chapman, Glenn AU - Dykes, James AU - Poon, David AU - Choo, Chinheng AU - Wang, Jun AU - Peng, Jun AU - Tu, Yuqiang A2 - Fieret, Jim A2 - Herman, Peter A2 - Okada, Tatsuo A2 - Arnold, Craig A2 - Bachmann, Friedrich A2 - Hoving, Willem A2 - Washio, Kunihiko A2 - Lu, Yongfeng A2 - Geohegan, David A2 - Trager, Frank A2 - Dubowski, Jan PY - 2005/// UR - http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PSISDG005713000001000247000001&idtype=cvips&gifs=yes ER -