Figure 1
Models of partly relaxed epitaxial Ge(001) layers on Si(001) substrates. (a) Crystal lattices of a relaxed Ge(001) layer on an Si(001) substrate. (b) Conventional relations of a Ge(001) epitaxial layer on Si(001). aS and cS are the lattice constants of the bottom Si(001) layer. aL,R and cL,R are the relaxed lattice constants of the top Ge(001) layer. aL and cL are the actual or strained lattice constants of the top Ge(001) layer. (c) Coincidence-site lattices of a Ge(001) epitaxial layer on Si(001). Axes X and Y correspond to sample basis axes S1 and S2. Relaxation vectors R1 and R2 have directions [\boldPhi_{1}] and [\boldPhi_{2}] of the sample principal basis and length values corresponding to relaxation degree. Gray circles mark out coinciding pairs of lattice nodes - anchors A1{Ge[110]; Si[110]}, A2{Ge[[\overline{1}10]]; Si[[\overline{1}10]]}. (d) Demonstration of anisotropic relaxation of an epitaxial layer. Relaxation vectors R1 and R2 show the directions of relaxation and strain degree.  [article HTML]