SEMICONDUCTOR ELEMENT EMPLOYING NITRIDE BASED SEMICONDUCTOR

• Main Authors: SUGIURA RISA, FUJIMOTO HIDETOSHI, NISHIO JOSHI
• Format: Patent
• Language: English
• Published: 06.03.1998
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; DEVICES USING STIMULATED EMISSION; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PROBLEM TO BE SOLVED: To suppress crystal defects on the interface to a substrate by varying the crystallinity of the buffer layer of a nitride-based semiconductor element, formed on a signal crystal substrate to increase stepwise or continuously from the signal crystal substrate. SOLUTION: A sapphire substrate 101 is subjected to vapor phase etching at 1200 deg.C for about 10min, in order to remove native oxide and then cooled down to 550 deg.C. It is then heated up to 1100 deg.C for 12min, while feeding 5L/min of hydrogen, nitrogen and ammonia and 30cc/min of TMG for about 2min. Subsequently, it is held at 1100 deg.C for about 2min, thus forming a GaN buffer layer 102. Consequently, a half-band width on the order of 60 arcmin, relatively close to that of polycrystal, is attained on the substrate side and a half-band width on the order of 5 arcmin, relatively close to that of single crystal, is attained on the surface side. Since the buffer layer 102 is provided with a substantially polycrystalline layer on the substrate 101 side, crystal defects on the interface to the substrate can be suppressed.