[111]-and [001]-Si single crystals were bombarded by high current pulsed electron beam (HCPEB) in energy density of 3?4 J/cm2. Surface morphologies of the irradiated Si samples were investigated with scanning electron microprobe. The results show that many craters were formed on the surface by 3 J/cm2 HCPEB. At 4 J/cm2 energy density

microcracks occurred on the bombarded surface. The shape of the microcracks was closely related to the crystal orientation of the bombarded sample. Under the HCPEB bombardment

severe plastic deformation occurred on the irradiated surface. Deformed shear bands were presented on the surface of [111]-Si

whereas the microbands are the dominating deformed microstructures on the bombarded surface of [001]-Si. In addition

a mass of micropores below 100 nm formed on the deformed regions

which provides a possibility of fabricating the surface porous materials.