Since its inception nearly 50 years ago, the semiconductor industry has utilized optical lithography to print ever-shrinking patterns on silicon wafers, thereby creating devices such as microprocessors and NAND Flash memory with ever increasing transistor densities. For the last two decades, lithographers have predicted the demise of optical lithography because of its presumed inability to print features smaller than the wavelength of light, leading to development of so-called next generation lithography (NGL) technologies such as extreme ultraviolet (EUV), hard X-ray, E-beam direct write (EBDW) or maskless, E-beam projection lithography (EPL), ion beam projection lithography (IPL) and 157nm. Each was designed to displace optical lithography but required costly new infrastructures, including new source, resist and photomask technologies, and have not proven to be economically or technically viable.
Presently, the industry workhorse is 193 immersion lithography, which means lithographically, there is no way to directly pattern features with a half pitch smaller than 40nm. Pitch reductions are now accomplished through a combination of 193i and self-aligned spacer double patterning (SADP) for half pitches down to 20nm and 193i and self-aligned spacer quadruple patterning (SAQP) for half pitches below 20nm. While in many cases this has allowed the industry to continue to advance Moore’s Law, the additional processing required (which includes many extra lithography, deposition and etch steps) after the primary lithography adds significant cost to every wafer processed. Nanoimprint Lithography (NIL) technology that can directly image the pattern of interest without additional processing extends the semiconductor roadmap while also substantially reducing cost.
Canon Nanotechnologies understands the semiconductor industry’s drive to continue to produce ever-shrinking features on silicon and has crafted its technology to leverage the existing optical lithography infrastructure, while providing a direct patterning solution. Canon’s NIL technology utilizes readily available I-line sensitive photoresist and source technology. In addition, NIL masks can be purchased from commercial mask makers such as Dai Nippon Printing, which use their existing photomask manufacturing lines to produce imprint masks. Canon Nanotechnologies is cooperating with manufacturers of mask and template writing tools, repair and inspection tools, and mask blank materials producers to help insure the reliability of the imprint mask supply chain.