Wang Ping, Wang Ding, Mondal Shubham, Wu Yuanpeng, Ma Tao, Mi Zetian
Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, United States.
Michigan Center for Materials Characterization, University of Michigan, Ann Arbor, Michigan 48109, United States.
ACS Appl Mater Interfaces. 2022 Apr 6;14(13):15747-15755. doi: 10.1021/acsami.1c23381. Epub 2022 Mar 25.
Monolithic integration of wurtzite III-nitrides with nonpolar silicon (Si), the two most-produced semiconductor materials, is essential and critical for a broad range of applications in electronics, optoelectronics, quantum photonics, and renewable energy. To date, however, it has remained challenging to achieve III-nitride heterostructures on Si with controlled lattice-polarity. Herein, we show that such critical challenges of III-nitrides on Si can be fundamentally addressed through a unique interfacial modulated lattice-polarity-controlled epitaxy (IMLPCE). It is discovered that the lattice-polarity of aluminum nitride (AlN) grown on Si(111) is primarily determined by the AlSiN interlayer: N-polar and Al-polar AlN can be achieved by suppressing and promoting the AlSiN interlayer formation, respectively. Furthermore, we develop a unique active-nitrogen-free annealing process to mitigate the AlSiN layer formation at the GaN/AlN interface, which can eliminate the inverted domain formation commonly seen in N-polar GaN on AlN/Si. This study provides an alternative approach for controlling the lattice-polarity of III-nitrides on Si substrates and will enable their seamless integration with the mature Si-based device technology.
纤锌矿型III族氮化物与非极性硅（Si）这两种产量最高的半导体材料的单片集成，对于电子、光电子、量子光子学和可再生能源等广泛应用至关重要且具有关键意义。然而，迄今为止，在硅上实现具有可控晶格极性的III族氮化物异质结构仍然具有挑战性。在此，我们表明，通过独特的界面调制晶格极性控制外延（IMLPCE）可以从根本上解决硅上III族氮化物的此类关键挑战。研究发现，在Si(111)上生长的氮化铝（AlN）的晶格极性主要由AlSiN中间层决定：分别通过抑制和促进AlSiN中间层的形成，可以实现N极性和Al极性的AlN。此外，我们开发了一种独特的无活性氮退火工艺，以减轻GaN/AlN界面处AlSiN层的形成，这可以消除在AlN/Si上的N极性GaN中常见的反向畴形成。本研究为控制硅衬底上III族氮化物的晶格极性提供了一种替代方法，并将使其能够与成熟的硅基器件技术无缝集成。
