AlN and AlGaN layers grown on Si(111) substrate by mixed-source hydride vapor phase epitaxy method

Abstract

High Al-composition AlGaN and AlN epilayers were grown directly on Si(111) substrate by a hydride vapor phase epitaxy (HVPE) method with a melted mixed source in a graphite boat set in a source zone with high temperatures of T = 700 and 800 °C, respectively. The presence of the Ga material in the mixed source of Ga and Al promoted the growth of AlN and AlGaN epilayers in the growth zone. When the temperature in the source zone was 800 °C, the crystalline quality of the AlN and AlGaN epilayers increased as the ratio of Ga to Al increased, and the optimum mix ratio of Ga to Al for the growth of AlN epilayers was approximately 0.35–0.42, obtained from a numerical fitting analysis of the X-ray diffraction (XRD) data for these epilayers. It appears that they can be grown directly by our melted-mixed-source HVPE method in a high-temperature source zone.

Vertical‐Type Blue Light Emitting Diode by Mixed‐Source Hydride Vapor Phase Epitaxy Method

“…The mixed‐source HVPE method has been applied to a nitride‐based semiconductor material . Figure (a) shows a schematic drawing of a cross‐sectional reactor, which was composed of a source zone with an RF heating‐coil to attain temperatures ( T > 900 °C) higher than the Al melting point (approximately 660 °C) on the outside, a multi‐graphite boat filled with the mixed source for consecutive growth of the epitaxial layers of the LED on the inside, and a growth zone with three furnaces.…”

“…The growth of the 170‐µm‐thick n‐type GaN:Si layer at 1090 °C and 0.7 µm min −1 from the mixed‐source (Ga + Si) contained in the second boat progresses. Figure (e) and (f) show the schematic drawing and SEM image, respectively, of the epilayer connected by the trapezoidal pillar arms grown along the direction originating from the top of the n‐type GaN pyramids with increasing the growth time in the growth of the 170‐µm‐thick n‐type GaN:Si layer. The scale bar is 20 µm.…”

“…In this work, a vertical‐type BLED was manufactured without using a conventional substrate by the mixed‐source HVPE method of a previously developed experimental process. The apparatus consisted of a multi‐graphite boat filled with the mixed source for consecutive growth and to control the growth rate by regulating the mixed‐source quantities inside the source zone; an RF heating coil to attain high temperatures, T > 900 °C, outside the source zone; and three furnaces in the growth zone of the reactor.…”

Fabrication of selective-area growth InGaN LED by mixed-source hydride vapor-phase epitaxy

“…The setup is different from that of previously reported HVPE methods. [23][24][25][26][27][28][29][30][31] The fabrication of the LED by the mixedsource HVPE method is based on the consecutive growth of all epitaxial layers using a multi-graphite boat filled sequentially with mixed-source materials in the source zone at high temperatures (T > 900 °C). 23) This mixed-source HVPE method has the advantages of low manufacturing cost owing to the reduced number of manufacturing steps, consecutive growth of epilayers using the multi-graphite boat, and ease of doping by regulating the mixing ratio of source materials.…”

“…As a result, we have successfully grown a high-quality AlN epilayer directly on a patterned sapphire substrate (PSS), 28) and AlN and high-Al-composition AlGaN epilayers on Si(111) substrates. 29) The InGaN epilayer has been grown mainly by metal organic chemical vapor deposition (MOCVD). [1][2][3][4][5][15][16][17][18][19] In this paper, we will report the development of InGaN LEDs with active layers grown using mixed-source InGaN materials on n-type GaN substrates by a selected-area growth (SAG) method and three fabrication steps: photolithography, epitaxial layer growth, and metallization; a previously reported experimental process using a mixed-source HVPE apparatus was used for this experiment.…”