Vacuum High Temperature Oven with Graphitic Isolation

蓝宝石衬底上高缺陷（~ 1011 cm-2）溅射沉积AlN层的高温退火（HTA）最近被证明是一种很有前途的缺陷减少方法。AlN证明了自己是少数几种可以在高温下退火而不解离的化合物半导体之一，类似于硅。在缺陷退火过程中，溅射层被加热到1750℃。到目前为止，高温退火大多采用氮气气氛。同时，根据相图的考虑，有明确的实验迹象表明，在CO或NH3等反应气体气氛下的退火步骤可能导致AlN的稳定，从而使在更高温度下退火成为可能。高温下的HTA工艺旨在进一步提高晶体质量。因此，我们建议购置带有石墨加热器和石墨绝热层的高温真空炉。这项计划中的工作不仅从科学的角度来看很有趣，而且还将为更高效的uv - led和氮基电力电子技术提供支持，其中泄漏电流对螺杆位错的密度反应敏感。总的来说，建议的炉应提供反应气体气氛（H2， CO, NH3）和惰性/反应气体混合物，温度至少为1750°C。

The high temperature annealing (HTA) of highly defective (~ 1011 cm-2) sputter-deposited AlN layers on sapphire substrates recently turned out to be a promising method for defect reduction. AlN proved itself as one of the few compound semicondutors that can be annealed at high temperatures without dissociation, similiar to silicon. During the defect annealing process, the as-sputtered layers are heated to temperatures up to 1750 °C. So far, mostly nitrogen atmospheres are used during high temperature annealing. Meanwhile, there are clear experimental indications, backed by phase diagram considerations, that an annealing step under reactive gas atmosphere e.g. CO or NH3 may lead to stabilization of the AlN and thus makes annealing at even higher temperatures possible. The HTA process at higher temperatures targets for an further increase of crystal quality.Therefore, we propose the acquisition of a high temperature vacuum furnace with a graphite heater and a graphite thermal insulation. The planned work is not only interesting from a scientific point of view, but would result in an enabling technology for more efficient UV-LEDs as well as nitride-based power electronics, where leakage currents react sensitive to the density of screw dislocations. Overall, the proposed furnace should offer reactive gas atmospheres (H2, CO, NH3) and inert/reactive gas mixtures at temperatures up to at least 1750 °C.