A new removable resist for high aspect ratio applications

Abstract

A variety of different photo resists are used for fabrication of MEMS. Presently good results were reported for SU-8, a chemically amplified negative tone photoresist. But SU-8 has a disadvantage for some applications in LIGA technique, especially in the X-ray mask fabrication. After processing the finished resist pattern are hardly soluble from the substrate. This paper will briefly describe the current status of the development of the new negative tone photoresist CAR 44 whose big advantage is the easy removableness of the cross linked pattern.

Photo‐embossed Surface Relief Structures with an Increased Aspect Ratios by Addition of a Reversible Addition‐Fragmentation Chain Transfer Agent

“…Other applications might be found in biomedical or optical applications for which higher aspect ratios are necessary. [24][25][26] …”

A self-aligned aperture-microlens array

“…Only the light passing through the lens surface was focused to selectively photo-crosslink the portion of the N-PR that was self-aligned with each lens of the MLA. 23 Fig. 3b presents a cross sectional SEM image showing a "sea island MLA" and N-PR on the top and bottom surface, respectively, the selective portion of which is photo-crosslinked by UV irradiation through each lens in the MLA.…”

From 2D Lithography to 3D Patterning

“…In 3D processing, there is no common manufacturing technology, dual side processing is customary, substrate topography can be several 100 Pm and resist films are sometimes very thick, leading to long exposure and development times etc. Therefore, the ECS Transactions, 33 (12) 55-70 (2010) 10.1149/1.3501034 © The Electrochemical Society lithographic requirements for 3D micro fabrication are more diverse. The main consequences of this diversity for alignment and exposure are discussed below.…”

“…But nowadays, chemically amplified photo-resist (CAR), sensitive for I-line exposure are available. CAR like SU-8 [11], NR44 [12] (both negative tone) or SIPR7120 [13] (positive tone) requires much lower exposure energies compared with conventional I-line photoresist, providing an interesting alternative.…”