Nowadays semiconductor chips aren't cleaved any more, but sawed.
Still, usually {100} or {110} cutting planes' orientation of the wafers are preferred, mainly because of the well-defined (anisotropic) etch-rates, see e.g. this freely accessible IEEE paper.
Back in the day the Nice Ladies in the assembly lab used
a diamond scribe and then rolled the blue filmed wafer
over a #2 pencil. Scribe stress riser trumps material
plane. We ran a variety of materials systems, single
crystal silicon, polysilicon handle SOI, bonded wafer
and SIMOX SOI. They treated it all the same (bit of
an art, having tried it once myself and made only shards).
But now, yeah, either laser scribe or diamond saw.