Overcoming the pseudomorphic critical thickness limit using compliant substrates

摘要

We demonstrated the highhyphen;quality molecular beam epitaxy growth of exceedingly thick In0.14Ga0.86As pseudomorphic layers on thin, freehyphen;standing, compliant GaAs substrates. We first fabricated 800hyphen;Aring;hyphen;thick compliant platforms before growing a latticehyphen;mismatched layer on the platform. The layer we grew exceeds its usual critical thickness by about twenty times without strain relaxation. Xhyphen;ray analysis confirms a shift in the InGaAs peaks grown on the compliant substrate, indicating an unrelaxed strain of 0.9percnt;. Moreover, atomic force microscope profiles verify that layers grown on compliant substrates are much smoother than layers grown on a plain substrate.