Quantum electron beam probe of sidewall dry-etch damage

Damage as a result of ion bombardment may occur both at top surfaces and at sidewalls. We propose a method of probing sidewall damage using coherent e lectron focusing. A collimated electron beam is reflected off an internal b oundary formed by dry etching. Spectra measured in an applied magnetic fiel d are influenced strongly by increased levels of etch damage. Monte Carlo s imulations combined with experiments on multiple beams reveal the separate contributions of boundary roughness and inelastic electron scattering. Elec trostatic calculations reveal a damage shadow beneath the sidewall.