Structural changes have been studied as a function of deposition temperature Ts in intrinsic a-Si:H and a-Ge:H. Bond angle disorder as indicated by the halfwidth of the transverse optic (TO) like Raman band is minimized at Ts ≈ 500K in a-Ge:H from different deposition methods, whereas in a-Si:H this ‘structural equilibration temperature’ is strongly dependent on growth conditions. Minimum disorder is found at Ts ≈ 460K in optimum quality a-Si:H, but occurs at Ts ≈ 550K in a-Si:H films from a 90 MHz discharge. Moreover Urbach energy and defect density from Photothermal Deflection Spectroscopy show a minimum at Ts ≈ 550K for all a-Si:H samples.