Publications

Lenhart, Joseph L.

Abstract not provided.

Lenhart, Joseph L.; King, Saskia H.

Abstract not provided.

Proposed for publication in Applied Surface Science.

Lenhart, Joseph L.

Abstract not provided.

Lenhart, Joseph L.; Cole, Phillip J.

Abstract not provided.

Proposed for publication in Advanced Materials.

Lenhart, Joseph L.; Cole, Phillip J.

Abstract not provided.

Lenhart, Joseph L.

Abstract not provided.

Langmuir

Lenhart, Joseph L.; Wu, Wen I.

X-ray reflectivity was used to characterize the thermal expansion of thin cross-linked polymer films. Changing the molecular mass of the hardener varied the cross-link density of the network. When the smaller-molecular-mass hardener was used, no changes in the apparent glass transition temperature (CTE) were observed in the thin films. When the larger-molecular-mass hardener was used, a transition from bulk to confined expansion occurred near 200 Å, where thinner films exhibit smaller rubbery expansion coefficients. For the lower cross-link density network, the thermal expansion behavior of the films was independent of the substrate surface treatment.

Proposed for publication in Langmuir.

Lenhart, Joseph L.; Lenhart, Joseph L.

We utilize near edge X-ray absorption fine structure spectroscopy (NEXASFS) to provide detailed chemical insight into two interfacial problems facing sub-100 nm patterning. First, chemically amplified photo-resists are sensitive to surface phenomenon, which causes deviations in the pattern profile near the interface. Striking examples include T-topping, closure, footing, and undercutting. NEXAFS was used to examine surface segregation of a photo-acid generator at the resist/air interface and to illustrate that the surface extent of deprotection in a model resist film can be different than the bulk extent of deprotection. Second, line edge roughness becomes increasingly critical with shrinking patterns, and may be intimately related to the line edge deprotection profile. A NEXAFS technique to surface depth profile for compositional gradients is described with the potential to provide chemical information about the resist line edge.