The non-polar class="mathmlsrc">title="View the MathML source" class="mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0749603616301926&_mathId=si1.gif&_user=111111111&_pii=S0749603616301926&_rdoc=1&_issn=07496036&md5=e25161fcb7999aa5de6f4b42b34b1fdf">class="imgLazyJSB inlineImage" height="17" width="40" alt="View the MathML source" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0749603616301926-si1.gif">class="mathContainer hidden">class="mathCode">$\left(11\overline{2}0\right)$-oriented a-plane AlGaN epi-layers were grown by MOCVD.

Si-induced strain relaxation in the non-polar AlGaN epi-layers can be promoted.

The crystal quality for both AlGaN epi-layers can be improved by Si-doping.

Si-doping efficiency of AlGaN samples was degraded at SiH₄ flow rate of 40 sccm.