Ion-beam resists

Note 2 A resist material that is optimized for use with ultraviolet or visible light, an electron beam, an ion beam, or X-rays is called a photoresist (see [2], p. 307), electron-beam resist, ion-beam resist, or X-ray resist, respectively. 

MAJOR APPLICATIONS Replacement for glass. Can be used as one-component-deep UV, electron-beam, or ion-beam resists in the manufacture of microelectronics chips. 

Almost all polymers are more sensitive (require fewer exposure units) when exposed to ion beams than when they are exposed to e-beams. Polymers such as styrene and novolac, which are relatively insensitive to e-beams, have a much more sensitive response to ion beams. However, resist speed is important for focused ion beam lithography and several high speed resists have been found, Poly(2,2,2-trifluoroethyl a-chloroacrylate), a scissioning positive tone polymer, and two cross-linking negative tone polymers, poly(2,5-dichlorostyrene) and poly(4-bromostyrene), have been found to function at high speed as ion beam resists. ... 

To achieve smaller dimensions there are systems that use x-rays instead of optical photons (150). These systems require a collimated x-ray source which is often expensive. Additionally, systems have been developed that use ion beams to expose the resist. Either an x-ray or ion beam system requires specialized resists and exposure systems. 

Resists used to define circuit patterns are radiation-sensitive and may be either positive- or negative-working. As a result of the fine lines, there has been movement away from optical Hthography and iato the mid- or deep-uv regioas. Developmeatal work has also beea focused oa electroa beam, x-ray, and ion-beam exposure devices and resists (9,10). 

Toshiyuki, Hayashi, Akihito, Matsumuro, Mutsuo, Mura-matsu, Masao, Kohzaki, and Katsumi, Yamaguchi, "Wear Resistance of Carbon Nitride Thin Films Formed by Ion Beam Assisted Deposition," Thin Solid Films, Vol. 376, No. 1-2, 2000,pp. 152-158. 

Preliminary experiments with electron-beam writing and ion-beam projection lithography have demonstrated that the S-layer may also be patterned by these techniques in the sub-lOO-nm range (nnpnblished resnlts). The combination of ion-beam projection lithography and S-layers as resist might become important in the near fntnre, since ion beams allow the transfer of smaller featnres into S-layer lattices compared to optical lithography. 

Ionizing radiation. Further studies on the effects of ionizing radiation such as 60Co y-ray radiation and ion beams on polysilanes have been reported.295 304-306 Both positive and negative resist properties can be shown, depending on the side-chain type, branch density, and the presence or absence of radical initiators. 

High resolution negative resists are needed for masked ion beam lithography (MIBL) and for the fabrication of MIBL masks by E-beam lithography (EBL). The MOTSS copolymer resists were developed to obtain the resolution of fine features that a bilevel resist can best provide. The flexibility afforded by choosing the structure of the HS, the copolymer composition, and the molecular weight allows a resist to be tailored by simple synthesis adjustments to have the particular sensitivity and etch protection which best suits the application. 

The synthesis of AIN described by Janes et al. (2003) may be mentioned as an example. The applications of this compound, mainly as a management material for silicon-based electronics, have been summarized together with its relevant properties (low coefficient of thermal expansion, close to that of Si, high thermal conductivity, high resistivity and low dielectric constant). Different preparation methods, often involving complex instruments, have been mentioned ion beam evaporation,... 

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