Metal-chalcogenide resists

Numerous compositions of metal-chalcogenide resists have been reported/ Generally, these resist systems contain a source of silver on the surface of a chalco-genide glass, e.g., As2S3 or Ge Sci. ,. (see Fig. 6.4). The thin Ag source may be 

Ag source, e.g., Ag, AgCl, or Ag2Se Chalcogenide glass, e.g., AS2S3 or Go jSei  

Shimizu, H. Sakuma, H. Kokado, and E. Inoue, The photo doping of metals into solids for new type imaging systems, Bull. Chem. Soc. Jpn. 44,1173 (1971) T. Shirakawa, I. Shimizu, H. Kokado, and E. Inoue, Photogr. Sci. Eng. 19, 139 (1975) M. Kasai and Y. Hajimoto, The photodoping sen sitivity in As S andGe S films, 7. App/. Phys. 47(8), 3595 (1976) M.S. Chang and J.T. Chen, A dry etched inorganic resist, App/. Phys. Lett. 33(10), 892 (1978). 

Shirakawa, I. Shimizu, H. Kokado, andE. Inoue, Photogr. Sci. Eng. 19,139 (1975) M.S. Chang and J.T. Chen, A dry etched inorganic resist, Appl. Phys. Lett. 33(10), 892 (1978). 

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NiAss octahedra share edges in one direction (the ab plane) and faces in another (along the c direction). Many transition metal chalcogenides with a 1 1 cation to anion ratio have this structure, for example, NiS, FeS, FeTe, CoTe, and CrSe. Some of these cannot possibly be considered ionic. For example, below 260 K, NiS is a semimetal (the resistivity is 10 fl cm and temperature independent) and metallic above 260 K (with a resistivity as low as 10 fl cm that increases with temperature), the transition not being accompanied by a change in the symmetry of the crystal structure (Imada et al., 1998). 

A major drawback of these chalcogenide resist systems is the contamination risk that their metallic ions and atoms pose to devices fabricated with them, should such contaminants not he properly cleaned off from such devices. Some of these chalcogenide resists are also very poisonous. 

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