Fabrication of GaN with Buried Tungsten (W) Structures Using Epitaxial Lateral Overgrowth (ELO) via LP-MOVPE

1999 ◽  
Vol 595 ◽  
Author(s):  
Hideto Miyake ◽  
Motoo Yamaguchi ◽  
Masahiro Haino ◽  
Atsushi Motogaito ◽  
Kazumasa Hiramatsu ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Catalytic Effect ◽  
Low Pressure ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Epitaxial Lateral Overgrowth ◽  
Severe Damage ◽  
Metal Mask ◽  
Lateral Overgrowth ◽  
Window Region

AbstractA buried tungsten (W) mask structure with GaN is successfully obtained by epitaxial lateral overgrowth (ELO) technique via low-pressure metalorganic vapor phase epitaxy (LP-MOVPE). The selectivity of GaN growth on the window region vs. the mask region is good. An underlying GaN with a striped W metal mask is easily decomposed above 500 °C by the W catalytic effect, by which radical hydrogen is reacted with GaN. It is difficult to bury the W mask because severe damage occurs in the GaN epilayer under the mask. It is found that an underlying AlGaN/GaN layer with a narrow W stripe mask width (mask/window = 2/2 νm) leads the ELO GaN layer to be free from damage, resulting in an excellent W-buried structure.

scholarly journals Fabrication of GaN with Buried Tungsten (W) Structures Using Epitaxial Lateral Overgrowth (ELO) via LP-MOVPE

2000 ◽  
Vol 5 (S1) ◽  
pp. 62-68
Author(s):  
Hideto Miyake ◽  
Motoo Yamaguchi ◽  
Masahiro Haino ◽  
Atsushi Motogaito ◽  
Kazumasa Hiramatsu ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Catalytic Effect ◽  
Low Pressure ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Epitaxial Lateral Overgrowth ◽  
Severe Damage ◽  
Metal Mask ◽  
Lateral Overgrowth ◽  
Window Region

A buried tungsten (W) mask structure with GaN is successfully obtained by epitaxial lateral overgrowth (ELO) technique via low-pressure metalorganic vapor phase epitaxy (LP-MOVPE). The selectivity of GaN growth on the window region vs. the mask region is good. An underlying GaN with a striped W metal mask is easily decomposed above 500 °C by the W catalytic effect, by which radical hydrogen is reacted with GaN. It is difficult to bury the W mask because severe damage occurs in the GaN epilayer under the mask. It is found that an underlying AlGaN/GaN layer with a narrow W stripe mask width (mask/window = 2/2 μm) leads the ELO GaN layer to be free from damage, resulting in an excellent W-buried structure.

Fabrication of GaN layer with Low Dislocation Density using Facet controlled ELO technique

2000 ◽  
Vol 639 ◽  
Author(s):  
H. Miyake ◽  
H. Mizutani ◽  
K. Hiramatsu ◽  
Y. Iyechika ◽  
Y. Honda ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Vapor Phase ◽  
Low Pressure ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Epitaxial Lateral Overgrowth ◽  
Lateral Overgrowth ◽  
Low Dislocation Density ◽  
Window Region

ABSTRACTGaN layers with low dislocation density have been fabricated be means of facet-controlled epitaxial lateral overgrowth (FACELO) via low-pressure metalorganic vapor phase epitaxy (LP-MOVPE). The distribution of the dislocations in FACELO GaN was inspected by observation of InGaN growth pits. For FACELO with {11-20} facets as the first step, the dislocations concentrate only in the window region. For FACELO with {11-22} facets as the first step, the dislocations exist only in the coalescence region. The double FACELO, which was FACELO with {11-20} on FACELO with {11-22}, was demonstrated and dislocation density of less than 105 cm−2 was achieved.

scholarly journals Hydrogen and Nitrogen Ambient Effects on Epitaxial Lateral Overgrowth (ELO) of GaN VIA Metalorganic Vapor-Phase Epitaxy (Movpe)

1999 ◽  
Vol 4 (S1) ◽  
pp. 118-123 ◽  
Author(s):  
Kazuyuki Tadatomo ◽  
Yoichiro Ohuchi ◽  
Hiroaki Okagawa ◽  
Hirotaka Itoh ◽  
Hideto Miyake ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Smooth Surface ◽  
Xrd Analysis ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Epitaxial Lateral Overgrowth ◽  
Mixture Ratio ◽  
Lateral Overgrowth ◽  
Ambient Gases ◽  
Image Position

Ambient gas effect on the epitaxial lateral overgrowth (ELO) of GaN via metalorganic vapor-phase epitaxy (MOVPE) on a MOVPE-grown GaN (0001) / sapphire (0001) substrate with a SiO2 stripe mask has been studied by means of field-emission scanning electron microscopy (SEM) and highresolution X-ray diffraction (XRD) analysis. Different ambient gases of nitrogen, hydrogen and their mixture (mixture ratio, hydrogen : nitrogen = 1 : 1) affect the lateral overgrowth rate, the surface morphology and the crystalline tilting of ELO-GaN layers. XRD revealed that the ELO-GaN layer on the SiO2 mask aligned along the <100> direction exhibited anisotropic crystalline tilting toward <110>. For ELO-GaN growth in nitrogen ambient, the growth rate of the (0001) facet decreases, the lateral overgrowth rate increases and the tilting of the ELO-GaN layer increases, while no smooth surface is obtained, in comparison with ELO-GaN growth in hydrogen ambient. For the mixture ambient, a smooth surface with a fast lateral overgrowth rate is achieved and the dislocation density is not more than 107 cm−2, which is comparable to that in hydrogen ambient.

Review of Facet Controlled Epitaxial Lateral Overgrowth (FACELO) of GaN via Low Pressure Vapor Phase Epitaxy

2000 ◽  
Vol 639 ◽  
Author(s):  
Kazumasa Hiramatsu ◽  
Hideto Miyake
Keyword(s):  
Vapor Phase ◽  
Low Pressure ◽  
Growth Conditions ◽  
Vapor Phase Epitaxy ◽  
Epitaxial Lateral Overgrowth ◽  
Propagation Mechanism ◽  
Threading Dislocations ◽  
Facet Structure ◽  
Lateral Overgrowth ◽  
Window Area

ABSTRACTFacet structures of GaN grown by epitaxial lateral overgrowth (ELO) via low pressure-metalorganic vapor phase epitaxy (LP-MOVPE) are controlled by growth conditions such as reactor pressure and growth temperature, where this technique is called FACELO (Facet Controlled ELO). The mechanism of the morphological change is discussed based on stability of the surface atoms. The propagation mechanism of the threading dislocations for the different GaN facet structure is also investigated. The distribution and density of the threading dislocations are observed by the growth pit density (GPD) method. Two typical models employing the FACELO are proposed; in one model, the dislocation concentrates only on the window area and, in the other model, only in the coalescence region in the center of the mask. In the latter model, the dislocation density is dramatically dropped to the order of 105−6 cm−2 with good reproducibility.

Selective Area Growth (SAG) and Epitaxial Lateral Overgrowth (Elo) of GaN Using Tungsten Mask

1998 ◽  
Vol 537 ◽  
Author(s):  
Yasutoshi Kawaguchi ◽  
Shingo Nambu ◽  
Hiroki Sone ◽  
Masahito Yamaguchi ◽  
Hideto Miyake ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Epitaxial Lateral Overgrowth ◽  
Selective Area Growth ◽  
Crystal Axis ◽  
Lateral Overgrowth ◽  
Selective Area ◽  
Area Growth

AbstractSelective area growth (SAG) and epitaxial lateral overgrowth (ELO) of GaN using tungsten (W) mask by metalorganic vapor phase epitaxy (MOVPE) and hydride vapor phase epitaxy (HVPE) have been studied. The selectivity of the GaN growth on the W mask as well as the SiO2 mask is excellent for both MOVPE and HVPE. The ELO-GaN layers are successfully obtained by HVPE on the stripe patterns along the <1100> crystal axis with the W mask as well as the SiO2 mask. There are no voids between the SiO2 mask and the overgrown GaN layer, while there are triangular voids between the W mask and the overgrown layer. The surface of the ELO-GaN layer is quite uniform for both mask materials. In the case of MOVPE, the structures of ELO layers on the W mask are the same as those on the SiO2 mask for the <1120> and <1100> stripe patterns. No voids are observed between the W or SiO2 mask and the overgrown GaN layer by using MOVPE.

Hydrogen and Nitrogen Ambient Effects on Epitaxial Lateral Overgrowth (ELO) of GaN Via Metalorganic Vapor-Phase Epitaxy (MOVPE)

1998 ◽  
Vol 537 ◽  
Author(s):  
Kazuyuki Tadatomo ◽  
Yoichiro Ohuchi ◽  
Hiroaki Okagawa ◽  
Hirotaka Itoh ◽  
Hideto Miyake ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Smooth Surface ◽  
Xrd Analysis ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Epitaxial Lateral Overgrowth ◽  
X Ray Diffraction ◽  
Mixture Ratio ◽  
Lateral Overgrowth ◽  
Ambient Gases

Ambient gas effect on the epitaxial lateral overgrowth (ELO) of GaN via metalorganic vapor-phase epitaxy (MOVPE) on a MOVPE-grown GaN (0001) / sapphire (0001) substrate with a SiO2 stripe mask has been studied by means of field-emission scanning electron microscopy (SEM) and high-resolution X-ray diffraction (XRD) analysis. Different ambient gases of nitrogen, hydrogen and their mixture (mixture ratio, hydrogen: nitrogen = 1: 1) affect the lateral overgrowth rate, the surface morphology and the crystalline tilting of ELO-GaN layers. XRD revealed that the ELO-GaN layer on the SiO2 mask aligned along the <1100> direction exhibited anisotropic crystalline tilting toward <1120>. For ELO-GaN growth in nitrogen ambient, the growth rate of the (0001) facet decreases, the lateral overgrowth rate increases and the tilting of the ELO-GaN layer increases, while no smooth surface is obtained, in comparison with ELO-GaN growth in hydrogen ambient. For the mixture ambient, a smooth surface with a fast lateral overgrowth rate is achieved and the dislocation density is not more than 107 cm-2, which is comparable to that in hydrogen ambient.

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