We employ an atomic force microscope to directly pattern the electron
system of InAs-AlSb surface quantum wells. Sharp and sturdy electron b
eam deposited tips are developed to withstand the comparatively high (
approximate to mu N) forces in the direct patterning process. By direc
t patterning the InAs surface quantum well we modulate the electron sy
stem without any mask. We are therefore able to directly transfer the
excellent lithographic resolution of atomic force microscopy to an ele
ctron system. The magnetoresistance of such fabricated antidot arrays
is discussed. (C) 1998 American Institute of Physics. [S0003-6951(98)0
4744-5]