Fabrication of full-color InGaN-based light-emitting diodes on amorphous substrates by pulsed sputtering

Abstract

InGaN-based light-emitting diodes (LEDs) have been widely accepted as highly efficient light sources capable of replacing incandescent bulbs. However, applications of InGaN LEDs are limited to small devices because their fabrication process involves expensive epitaxial growth of InGaN by metalorganic vapor phase epitaxy on single-crystal wafers. If we can utilize a low-cost epitaxial growth process, such as sputtering on large-area substrates, we can fabricate large-area InGaN light-emitting displays. Here, we report the growth of GaN (0001) and InGaN (0001) films on amorphous SiO2 by pulsed sputtering deposition. We found that using multilayer graphene buffer layers allows the growth of highly c-axis-oriented GaN films even on amorphous substrates. We fabricated red, green, and blue InGaN LEDs and confirmed their successful operation. This successful fabrication of full-color InGaN LEDs on amorphous substrates by sputtering indicates that the technique is quite promising for future large-area light-emitting displays on amorphous substrates.

N-polar InGaN-based LEDs fabricated on sapphire via pulsed sputtering

“…We have demonstrated that the growth mechanisms of PSD are inherently different from those behind the MOCVD growth, enabling the growth of high-quality nitride films at considerably lower growth temperatures owing to the enhanced surface migration of adatoms on the growth surfaces. [11][12][13][14][15][16][17] These features are also expected to facilitate the growth of high-quality N-polar nitride films because surface roughening in N-polar growth is probably caused by the insufficient surface migration of growth precursors.…”

“…11 In fact, high-quality n-type and p-type GaN with room-temperature (RT) carrier mobilities of 1008 cm 2 V 1 s 1 and 34 cm 2 V 1 s 1 , respectively, 12 have already been prepared, and various devices such as light-emitting diodes (LEDs), 13,14 solar cells, high-electron mobility transistors, 15 and metal-insulator semiconductor field-effect transistors 16 were fabricated via PSD. The PSD growth mechanism involves the enhanced surface migration of film precursors from the pulsed-supplied group-III metals.…”

Electron transport properties of degenerate n-type GaN prepared by pulsed sputtering

“…The use of PSD enables the growth of device-quality group-iii nitrides at much lower temperatures than those used in the conventional MOCVD process. [6][7][8][9][10][11] PSD is suitable for growing heavily impurity-doped GaN because of its highly nonequilibrium nature. In fact, heavily Si-doped GaN prepared by PSD exhibited a RT electron 13 These achievements in the growth of highly conductive, heavily doped n-type GaN provide a good opportunity for systematically investigating the transport properties of degenerate GaN.…”

Epitaxial growth of GaN films on nearly lattice-matched hafnium substrates using a low-temperature growth technique

“…8,10-13 Such low-temperature growth enables epitaxial growth of GaN and AlN films even on chemically vulnerable substrates such as metal because the interfacial reactions between nitride films and substrates are suppressed. [14][15][16][17] In this study, we have investigated the feasibility of epitaxial growth of GaN films on matched Hf (0001) substrates with small lattice mismatches using the low-temperature (LT) growth technique involving PXD.…”