[17a-B301-1~12] 15.1 Bulk crystal growth

[17a-B301-10] Application of Hollow Structures Using Atomic Layer Deposition

〇Tatsurou Sagawa¹, Masayuki Nakamura¹, Takayuki Kobayashi¹, Koichiro Yuki², Ryo Inomoto², Narihito Okada², Toshiaki Tatsuta¹, Kazuyuki Tadatomo², Shin-ich Motoyama¹ (1.Samco Inc., 2.Yamaguchi Univ.)

Keywords:ALD, Hollow structure, GaN

A low-defect GaN substrate is indispensable for the fabrication of GaN power devices. However, in the fabrication of GaN free-standing substrates using the HVPE method, it often happens cracking of the GaN substrate by thermal stress due to a large difference of thermal expansion coefficient between sapphire and GaN.Reducing the contact area between GaN and sapphire can prevent cracking of the GaN substrate. In this study, by making a hollow structure of AlN film with ALD on the sapphire substrate and using MOCVD method, we succeeded in epitaxial growth of smooth GaN on the surface to form surface morphology.