Epitaxial GaN using Ga(NMe2)3 and NH3 Plasma by Atomic Layer Deposition

Abstract

<jats:p>&lt;div&gt;Low temperature deposition of high-quality epitaxial GaN is crucial for its integration in&lt;/div&gt;&lt;div&gt;electronic applications. Chemical vapor deposition at approximately 800 °C using SiC with an&lt;/div&gt;&lt;div&gt;AlN buffer layer or nitridized sapphire as substrates is used to facilitate the GaN growth. Here,&lt;/div&gt;&lt;div&gt;we present a low temperature atomic layer deposition (ALD) process using&lt;/div&gt;&lt;div&gt;tris(dimethylamido)gallium(III) with NH3 plasma. The ALD process shows self-limiting&lt;/div&gt;&lt;div&gt;behaviour between 130-250 °C with a growth rate of 1.4 Å/cycle. The GaN films produced were&lt;/div&gt;&lt;div&gt;crystalline on Si(100) at all deposition temperatures with a near stochiometric Ga/N ratio with&lt;/div&gt;&lt;div&gt;low carbon and oxygen impurities. When GaN was deposited on 4H-SiC, the films grew&lt;/div&gt;&lt;div&gt;epitaxially without the need for an AlN buffer layer, which has never been reported before. The bandgap of the GaN films was measured to be ~3.42 eV and the fermi level showed that the GaN was unintentionally n-type doped. This study shows the potential of ALD for GaN-based&lt;/div&gt;&lt;div&gt;electronic devices.&lt;/div&gt;</jats:p>