INSTRUMENTATION OF A WAFER INSPECTION LARGE-SAMPLE ATOMIC-FORCE MICROSCOPE

Particle detection at the 0.1 mu m level has become increasingly impor tant in producing reliable devices that demand smaller line widths. Ho wever, because the position alignment accuracy between the commercial optical particle inspection system and the particle evaluation instrum ent is insufficient, it is extremely difficult to detect 0.1 mu m size particles. To solve these problems, we have succeeded in increasing t he coordinate positioning accuracy at the 0.1 mu m level by combining a large sample atomic force microscope (G. Bing, C. F. Quate and Ch. G erber, Phys. Rev. Lett., 56 (1986) 930) with an optical scattering sys tem. Using this system, we can now observe defects and particles on ba re wafers and the possibility of particle detection is virtually 1.00% . Furthermore, the observation time necessary to position on a particl e is substantially reduced.