GROWTH OF THICK GaN FILMS AND SEEDS FOR BULK CRYSTAL GROWTH

2004 ◽  
Vol 14 (01) ◽  
pp. 51-62 ◽  
Author(s):  
P. R. TAVERNIER ◽  
E. V. ETZKORN ◽  
D. R. CLARKE
Keyword(s):  
Crystal Growth ◽  
Dislocation Density ◽  
Growth Direction ◽  
Bulk Crystal ◽  
Hydride Vapor Phase Epitaxy ◽  
Threading Dislocation ◽  
Bulk Crystal Growth ◽  
Low Dislocation Density ◽  
Threading Dislocation Density ◽  
Compliant Layer

The essential steps required to create thick GaN films and seed crystals for bulk crystal growth are described. These include the growth of low dislocation density GaN films by hydride vapor phase epitaxy and the separation of films from their growth substrates. Also addressed are issues of processing thin and thick films to create compliant layer substrates for thick film HVPE growth and chemical mechanical polishing methods to enhance surface morphology and remove material damage free. Growth of both gallium and nitrogen polar films is discussed with key issues identified regarding polarity inversion during growth and impurity incorporation along the -c growth direction. These are illustrated with examples that emphasize the growth of material with low threading dislocation density.

Defect Formation During Sublimation Bulk Crystal Growth of Silicon Carbide

1998 ◽  
Vol 510 ◽  
Author(s):  
Noboru Ohtani ◽  
Jun Takahashi ◽  
Masakazu Katsuno ◽  
Hirokatsu Yashiro ◽  
Masatoshi Kanaya
Keyword(s):  
Silicon Carbide ◽  
Crystal Growth ◽  
Defect Formation ◽  
Stacking Faults ◽  
Growth Direction ◽  
Bulk Crystal ◽  
Structural Defects ◽  
Bulk Crystals ◽  
Bulk Crystal Growth ◽  
Sublimation Growth

AbstractThe defect formation during sublimation bulk crystal growth of silicon carbide (SiC) is discussed. SiC bulk crystals are produced by seeded sublimation growth (modified-Lely method), where SiC source powder sublimes and is recrystallized on a slightly cooled seed crystal at uncommonly high temperatures (≥2000°C). The crystals contain structural defects such as micropipes (hollow core dislocations), subgrain boundaries, stacking faults and glide dislocations in the basal plane. The type and density of the defects largely depend on the crystal growth direction, and many aspects are different between the growth parallel and perpendicular to the <0001> c-axis. Micropipes are characteristic defects to the c-axis growth, while a large number of stacking faults are introduced during growth perpendicular to the c-axis. We discuss the cause and mechanism of the defect formation

Estimating the Threading Dislocation Density of Thick GaN Films

2012 ◽  
Vol 433-440 ◽  
pp. 606-609 ◽  
Author(s):  
Ru Wang ◽  
Jun Ling Zhang ◽  
Rui Xia Yang ◽  
Xiu Jun Zhang
Keyword(s):  
Dislocation Density ◽  
Statistical Significance ◽  
Hydride Vapor Phase Epitaxy ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Etch Pit ◽  
Threading Dislocation Density ◽  
General Statistical ◽  
Gan Film

The threading dislocation density (TDD) of thick GaN films grown by hydride vapor phase epitaxy (HVPE) was estimated through counting etch pit density (EPD) and calculating full width at half maximum（FWHM）of double crystal X-Ray diffraction (DCXRD). TDD was about 108 through counting EPD, while it was about 109 through calculating the FWHMs of (0002) and (1012). The experiment results show that the two methods are both suited to estimating the TDD of the thick HVPE-GaN films with 350um thickness. But they have some difference: EPD method is fitter in evaluating the dislocation density of the surface of thick GaN film, but FWHM method can gain the total dislocation density of thick GaN film. The method calculating the FWHMs possesses more general statistical significance.

Estimating the Threading Dislocation Density of Thick GaN Films

2011 ◽  
Vol 383-390 ◽  
pp. 5264-5267
Author(s):  
Ru Wang ◽  
Jun Ling Zhang ◽  
Rui Xia Yang ◽  
Xiu Jun Zhang
Keyword(s):  
Dislocation Density ◽  
Statistical Significance ◽  
Hydride Vapor Phase Epitaxy ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Etch Pit ◽  
Threading Dislocation Density ◽  
General Statistical ◽  
Gan Film

The threading dislocation density (TDD) of thick GaN films grown by hydride vapor phase epitaxy (HVPE) was estimated through counting etch pit density (EPD) and calculating full width at half maximum(FWHM)of double crystal X-Ray diffraction (DCXRD). TDD was about 108 through counting EPD, while it was about 109 through calculating the FWHMs of (0002) and (10î2). The experiment results show that the two methods are both suited to estimating the TDD of the thick HVPE-GaN films with 350um thickness. But they have some difference: EPD method is fitter in evaluating the dislocation density of the surface of thick GaN film, but FWHM method can gain the total dislocation density of thick GaN film. The method calculating the FWHMs possesses more general statistical significance.

High-Irradiance Degradation Studies of Metamorphic 1eV GaInAs Solar Cells

2012 ◽  
Vol 1432 ◽  
Author(s):  
Ryan M. France ◽  
Myles A. Steiner
Keyword(s):  
Solar Cells ◽  
Active Region ◽  
Dislocation Density ◽  
Dark Current ◽  
Degradation Mechanism ◽  
Control Cell ◽  
High Irradiance ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Degradation Studies

ABSTRACTInitial tests are performed regarding the degradation of lattice-mismatched GaInAs solar cells. 1eV metamorphic GaInAs solar cells with 1-2×106 cm-2 threading dislocation density in the active region are irradiated with an 808 nm laser for 2 weeks time under a variety of temperature and illumination conditions. All devices show a small degradation in Voc that is logarithmic with time. The absolute loss in performance after 2 weeks illuminated at 1300 suns equivalent and 125°C is 7 mV Voc and 0.2% efficiency, showing these devices to be relatively stable. The dark current increases with time and is analyzed with a two-diode model. A GaAs control cell degrades at the same rate, suggesting that the observed degradation mechanism is not related to the additional dislocations in the GaInAs devices.

Relationship between misfit-dislocation formation and initial threading-dislocation density in GaInN/GaN heterostructures

2015 ◽  
Vol 54 (11) ◽  
pp. 115501 ◽  
Author(s):  
Motoaki Iwaya ◽  
Taiji Yamamoto ◽  
Daisuke Iida ◽  
Yasunari Kondo ◽  
Mihoko Sowa ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Misfit Dislocation ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Dislocation Formation

Enhanced reduction in threading dislocation density in Ge grown on porous silicon during annealing due to porous buffer reconstruction

2015 ◽  
Vol 213 (1) ◽  
pp. 96-101
Author(s):  
G. Calabrese ◽  
S. Baricordi ◽  
P. Bernardoni ◽  
D. De Salvador ◽  
M. Ferroni ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Dislocation Density ◽  
Threading Dislocation ◽  
Threading Dislocation Density
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