A NOVEL NANOLITHOGRAPHIC CONCEPT USING CRACK-ASSISTED PATTERNING AND SELF-ALIGNMENT TECHNOLOGY

An original technology for fabricating nano-objects as small as severa l nanometers in width using a new class of lithographic masks is descr ibed. Glassy films such as SiO2, SiNx(H), and others deposited from va por onto semiconductor substrates and capable of changing their volume and, hence, the internal stress during specific treatments, are used as a mask material. Using these film's features, a technology of mask formation is developed. Its originality consists of (i) making opening s in the masks by controlled introduction of cracks into the mask coat ing in prior prescribed places of the substrate and (ii) gradual contr olled variation of the crack width, thus achieving self-alignment of t he initial and final mask patterns. Using controlled cracking, narrow openings similar to 300 to similar to 17 nm wide have been formed in s ingle-and double-layer mask films. Narrow electrodes on silicon have b een produced by electrolytic deposition of Ni into the openings. It is also shown that the crack width can be controlled and sequentially va ried at a nanometer scale using special successive treatments. Thus, h igh precision repeatable self-alignment of mask pattern can be achieve d, which can be used in fabricating complex nanoscale devices.