LITHOGRAPHY WITH A 50 KV E-BEAM AND A VACUUM SCANNING TUNNELING MICROSCOPE IN A POLYDIACETYLENE NEGATIVE RESIST

We present complementary studies of high (50 KeV) and low (5 eV) energy e-beam lithography in a polydiacetylene negative resist. A 50 KV probe of 1/e radius 8.3 nm defined a minimum continuous linewidth of almost-equal-to 80 nm, with a dose of 1.7 nC/cm. The scanning tunneling microscope (STM) can image and lithographically pattern the resist in situ. Comparison of STM images of undeveloped lines to micrographs of developed lines show little difference in size. Lines, 55 nm wide, were produced by a 5 V probe with a line dose of 20-mu-C/cm. The latent images of the 5 V defined lines and the 50 KV defined lines both appear as depressions in the resist. The minimum feature sizes cannot be explained by the probe diameters, electron scattering, or resist swelling in the developer. The possible effect of resist chemistry on the minimum feature size is discussed.