Making a good impression: Nanoimprint lithography tests at NIST

In a paper published last fall,** NIST materials scientists addressed the first question. Using sensitive X-ray measurements they demonstrated that NIL could be used on a functional SOG material to transfer patterns with details finer than 100 nanometers with minimal distortion due to the processing. In a new paper this month,*** they extend this work to study the effect of the embossing process on the nanopore structure in the glass. Using a combination of techniques to measure the distribution of nanopores in the insulator material, they found that the NIL embossing process actually has a beneficial effect—it increases the population of small pores, which improve performance, reduces the population of larger pores that can cause problems and creates a thin, dense protective skin across the surface of the material. All of these effects are highly attractive for minimizing short circuits in semiconductor devices.

Taken together, the two papers suggest that nanoimprint lithography can produce superior nanoporous insulator layers in advanced semiconductor devices with significantly fewer—and easier—processing steps than conventional lithography.

* “Spin-on organosilicate glass”

** H.W. Ro, R.L. Jones, H. Peng, D.R. Hines, H-J. Lee, E.K. Lin, A. Karim, D.Y. Yoon, D.W. Gidley and C.L. Soles. The direct patterning of nanoporous interlayer dielectric insulator films by nanoimprint lithography. Advanced Materials. 2007, 19, 2919–2924.

*** H.W. Ro, H. Peng, K.-i. Niihara, H.-J. Lee, E.K. Lin, A. Karim, D.W. Gidley, H. Jinnai, D.Y. Yoon and C.L. Soles. Self-sealing of nanoporous low dielectric constant patterns fabricated by nanoimprint lithography. Advanced Materials 2008, Early View: April 15, 2008.