Positive-tone EUV resists: complexes of platinum and palladium

The EUV photoreactivity of platinum and palladium mononuclear complexes has been investigated. Many platinum and palladium complexes show little or no EUV sensitivity, however, we have found that metal carbonates and metal oxalates (L2M(CO3) and L2M(C2O4); M = Pt or Pd) are sensitive to EUV. The metal-carbonates give negative tone behavior. The most interesting result is that the metal oxalates give first positive-tone EUV resists based on mono-nuclear organometallic compounds. In particular, (dppm)Pd(C2O4) (dppm = 1,1-Bis(diphenylphosphino)methane) (25) prints 30-nm dense lines with Esize of 50 mJ/cm2. To improve the lithographic performance of (25), the processing conditions were studied. A bake study showed that bake affected sensitivity and dark loss very little, while dark loss worsened with development time. Derivatives of (25) were synthesized to explore the effect of molecular weight on resist sensitivity, but the study showed no correlation between molecular weight and sensitivity.

[1]  Jeffrey I. Zink,et al.  Photochemical cleavage of carbonate in cyclopentadiene carbonate rhodium complex (CpRh(CO3).cntdot.2H2O) , 1989 .

[2]  Yasin Ekinci,et al.  Evaluation of EUV resist performance with interference lithography towards 11 nm half-pitch and beyond , 2013, Advanced Lithography.

[3]  A. L. Prignano,et al.  Photochemical generation of bis(phosphine)palladium and bis(phosphine)platinum equivalents , 1985 .

[4]  F. R. Haratley.  The Chemistry of Platinum and Palladium , 1973 .

[5]  G.D. Hutcheson.  Extreme ultraviolet lithography: will it be ready in time? , 2001, IEEE Spectrum.

[6]  A. Vogler,et al.  Photochemistry of Azide Complexes of Gold, Silver, Platinum, and Palladium. Generation of the Metallic State , 1988 .

[7]  Yasin Ekinci,et al.  EUV resists based on tin-oxo clusters , 2014, Advanced Lithography.

[8]  Stefan Wurm,et al.  EUV Lithography , 2014, Proceedings of Technical Program - 2014 International Symposium on VLSI Technology, Systems and Application (VLSI-TSA).

[9]  G. Lumetta,et al.  Photochemical reactions of diphosphineplatinum(II) oxalate complexes , 1992 .

[10]  P ? ? ? ? ? ? ? % ? ? ? ? , 1991 .

[11]  Markos Trikeriotis,et al.  High refractive index and high transparency HfO2 nanocomposites for next generation lithography , 2010 .

[12]  Andrew Parkin,et al.  Nucleotide cross-linking induced by photoreactions of platinum(IV)-azide complexes. , 2003, Angewandte Chemie.

[13]  R. H. Stulen,et al.  Extreme ultraviolet lithography , 1998 .