Lithography and Other Patterning Techniques for Future Electronics

Review on Micro- and Nanolithography Techniques and their Applications

“…Photolithography has been the main workhorse in the semiconductor and IC industry [1][2][3][4][5][6][7][8][9][10]. It has been employed for pattern generation in manufacturing of ICs, microchips and commercial MEMS devices.…”

“…This patterned photo-resist can be used as a protective layer in subsequent etching or deposition processes to build topography on the substrate. 2-3 μm [22] very high typical patterning in laboratory level and production of various MEMS devices Photolithography (projection printing) a few tens of nanometers (37 nm) [2] high -very high (60-80 wafers/hr) [1] commercial products and advanced electronics including advanced ICs [1] , CPU chips Electron beam lithography < 5 nm [23] very low [1,3] (8 hrs to write a chip pattern) [1] masks [3] and ICs production, patterning in R&D including photonic crystals, channels for nanofluidics [23] Focused ion beam lithography 20 nm with a minimal lateral dimension of 5 nm [2] very low [3] patterning in R&D including hole arrays [125,134] , bull's-eye structure [132] , plasmonic lens [137] Soft lithography a few tens of nanometers to micrometers [2,13] (30 nm) [2] high LOCs for various applications [13,96] Nanoimprint lithography 6-40 nm [14,15,18] high (> 5 wafers/hr) [1] bio-sensors [17] , bioelectronics [18] , LOCs: nano channels, nano wires [97,102,104] Dip-pen lithography a few tens of nanometers [39,40,43] very low -low, possibly medium [39] bio-electronics [43] , biosensors [40] , gas sensors [42] There are three forms of photolithography: contact printing, proximity printing and projection printing as schematically illustrated in …”

“…In contrast, a projection printing system (so-called 'stepper') utilizes an optical lens system to project a deep-UV pattern from an excimer laser (wavelength of 193 or 248 nm) on the photo-resist enabling pattern-size reduction by 2-10 times. It is capable of fabricating highresolution patterns as small as a few tens of nanometers (37 nm) [2] at a high throughput wafers/hr) [1]. However, it requires a sophisticated optical-lens system and precise control systems of temperature and position resulting in a very expensive setup.…”

“…To increase the system throughput, multiaxis electron beam lithography [26,27] has been proposed. So far, the deployment of this technique in manufacturing process is still limited due to the difficulty in developing practical electron beam sources [1]. In the past, electron beam lithography was very expensive thus limiting the access.…”

“…Masked lithography makes use of masks or molds to transfer patterns over a large area simultaneously, thus, enabling a high-throughput fabrication up to several tens of wafers/hr. The forms of masked lithography include photolithography [1][2][3][4][5][6][7][8][9][10], soft lithography [11][12][13], and nanoimprint lithography [14][15][16][17][18][19][20][21]. On the other hand, maskless lithography, such as electron beam lithography [22][23][24][25][26][27][28][29], focused ion beam lithography [30][31][32][33], and scanning probe lithography [34][35][36][37][38][39][40][41][42][43][44], fabricates arbitrary patterns by a serial writing without the use of masks.…”