A study was made of crystals which were oriented 9º off-axis towards [011] and had undergone plastic deformation. Optical microscopy revealed that the substrates exhibited a cross-hatch pattern which consisted of ridges and trenches that extended in the [011] and [01¯1] directions. Further characterization of these features, using scanning tunnelling microscopy, showed that they consisted of bands of steps. The bands were created when a group of dislocations emerged onto the crystal surface from the bulk. The dislocations were of (a/2)<011> type.

Characterization of dislocations in germanium substrates S.Gan, L.Li, R.F.Hicks: Applied Physics Letters, 1998, 73[8], 1068-70