TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preparation: No preparation method is given. Preferred Components: The crystal further comprises: at least two single crystal domains having a gallium-containing nitride composition; a semiconductor structure fabricated on the first large area surface, where the semiconductor structure comprises at least one of epitaxial layer having a metal compound of formula AlxInyGa(1-x-y)N (I). The crystallographic orientation of the first large-area surface: has a crystallographic orientation that is miscut from a (10-100) m-plane by -30 degrees C to 30 degrees C, preferably -5 degrees C to 5 degrees C toward a (0001) +c-direction and by 5 degrees C, preferably 1 degrees C toward an orthogonal (1-210) a-direction; is within 5 degrees C of a semi polar orientation comprising planes as given in the specification. The first large-area surface: is characterized by an impurity concentration of: oxygen of 1x 1016-1x 1019 cm-3; hydrogen of 1x 1016-2x 1019 cm-3; fluorine and chlorine of 1x 1015-1x 1017 cm-3 ; and at least one of sodium and potassium of 3x 1015-1x 1018 cm-3; and comprises a root-mean-square surface roughness of 1 nm, which is measured over a 10 mu m area. The at least two single crystal domains: comprise a dislocation density within the domain less than 104 cm-2, a polar misorientation angle ( gamma ) between the first domain and the second domain of 0.01-0.5 degrees C, and azimuthal misorientation angles alpha and beta of 0.01-1 degrees C; are separated by a line of dislocations with a linear density of 1x 105 cm-1. The crystal comprises a substantially wurtzite structure that is substantially free of other crystal structures which are less than or equal to 1% in volume than a volume of the substantially wurtzite structure. The at least one of the first large area surface and the second large area surface is characterized by a dislocation density of 103 cm-2 and by a stacking fault concentration of 1 cm-1.x, y = 0; andx+y = 1.Preferred Method: The one of or both the first large area surface and the second large area surface are polished before the etching. The large-area surface closest in orientation to a (0001) plane is characterized by a dislocation density of below 104 cm-2, as determined by a first etching process in a melt comprising at least one of sodium hydroxide and potassium hydroxide at 300-500 degrees C for 30 seconds to 1 hour. An m-plane surface comprising a surface area of at least 3 mm2 is characterized by a dislocation density of below 104 cm-2, and is free of stacking faults, as determined by a second etching process comprising etching in a solution comprising phosphoric acid and sulfuric acid. EXAMPLE - No suitable example given.