Correlation of Selected Problems During Gan Movpe Epitaxy on si Substrates with in–Situ Interferometer Observation

Abstract In this paper, selected problems occurring during GaN epitaxy on Si substrates are correlated with in-situ interferometer observations based on structures fabricated using 3×2” Thomas Swan Close Coupled Showerhead MOVPE system. Samples were epitaxially grown on highly resistive (> 500cm) p-type 2” silicon substrates. The growth was observed using an interferometer acquiring reflectance traces in-situ. To avoid issues that are shown in this paper, different approaches of the so-called buffer layer were used by depositing them on Si before the growth of GaN. Different material qualities of grown GaN layers were obtained by variation in films constituting the buffer layer grown before the desirable GaN film. The study shows the evolution of the grown samples, improvement of various parameters and also gradual reduction of material issues discussed in this paper. Improvement in GaN layer was mainly observed by SEM characterization and studying the growth mechanisms through observation of reflectance traces obtained in-situ.

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In‐Situ Fabrication of YBa2Cu3O7‐x Superconducting Thin Films Directly on Silicon Substrates with Tc0 > 77K

MRS Proceedings ◽

10.1557/proc-169-481 ◽

1989 ◽

Vol 169 ◽

Author(s):

C. B. Lee ◽

R. K. Singh ◽

S. Sharan ◽

A. K. Singh ◽

P. Tiwari ◽

...

Keyword(s):

Thin Films ◽

Laser Pulses ◽

Superconducting Film ◽

Laser Evaporation ◽

Silicon Substrates ◽

Superconducting Thin Films ◽

Si Substrates ◽

In Situ Fabrication ◽

Substrate Temperatures

AbstractWe report in‐situ fabrication of c‐axis textured YBa2Cu3O7‐x superconducting thin films with Tco > 77K on unbuffered silicon substrates by the biased pulsed laser evaporation (PLE) technique in the temperature range of 550‐650°C. At substrate temperatures below 550°C, no c‐axis texturing of the superconducting film was observed. The YBa2Cu3O7‐x superconducting films were fabricated by ablating a bulk YBa2Cu3O7 target by a XeCl excimer laser (λ = 308 nm, τ = 45 × 10‐9 sec) in a chamber maintained at an oxygen pressure of 0.2 torr . The thickness of the films was varied from 0.3 to 0.5 nm depending on the number of laser pulses. Extensive diffusion was observed in thin films deposited at substrate temperatures above 550°C. However, microstructurally, with increase in the substrate temperature the films exhibited larger grain size and greater degree of c‐axis texturing (measured by the ratio of the (005) and (110) X‐ray diffraction peaks). This was found to give rise to better superconducting properties with Tco exceeding 77 K for YBa2Cu3O7‐x films deposited on Si substrates at 650°C.

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Investigation of an in-situ probe for phase transformations during RTP silicidation

MRS Proceedings ◽

10.1557/proc-260-145 ◽

1992 ◽

Vol 260 ◽

Cited By ~ 5

Author(s):

R. J. Schreutelkamp ◽

P. Vandenabeele ◽

B. Deweerdt ◽

W. Coppye ◽

C. Vermeiren ◽

...

Keyword(s):

Phase Transformation ◽

Thermal Degradation ◽

Phase Transformations ◽

Doping Level ◽

Polycrystalline Silicon ◽

Silicon Substrates ◽

Si Substrates ◽

Background Doping ◽

Emissivity Measurements

ABSTRACTIn-situ emissivity measurements at a wavelength of 2.4 μα were used to monitor RTP Co silicidation on crystalline and polycrystalline silicon substrates. The influence of various parameters influencing the silicidation reaction was extensively studied. It is shown that particularly the phase transformation from CoSi to the final suicide phase, COSi2, strongly depends on parameters such as background doping level and type of substrate. This is illustrated for As-doped substrates. The method is extremely sensitive for the in-situ detection of the thermal degradation of thin COSi2 films at high temperatures, which is demonstrated for 25 nm COSi2 layers on highly As-doped c-Si substrates.

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Growth and properties of epitaxial PbSe on Si(111) and Si(100) without buffer layer

MRS Proceedings ◽

10.1557/proc-379-133 ◽

1995 ◽

Vol 379 ◽

Author(s):

P. Müller ◽

A.N. Tiwari ◽

H. Zogg

Keyword(s):

Buffer Layer ◽

Lattice Mismatch ◽

Infrared Detector ◽

Device Fabrication ◽

Buffer Layers ◽

Silicon Substrates ◽

High Quality ◽

Si Substrates ◽

Large Lattice ◽

Large Lattice Mismatch

Narrow gap IV-VI materials like PbS, PbSnSe and PbSnTe are used for infrared detector device fabrication [1,2]. Earlier an intermediate Ila-fluoride buffer layer, which consisted of a BaF2/CaF2-stack of about 2000 Å thickness, was used to get epitaxial high quality layers on silicon substrates. This buffer is now reduced to a much thinner layer of only about 20 Å thick CaF2, regardless the large lattice mismatch between layer and substrate [3,4,5]. The question therefore arises if high quality IV-VI layers can be grown on Si-substrates without any buffer layer as e.g. in CdTe/Si or GaAs/Si systems.The aim of this work is to grow IV-VI layers directly on Si-substrates without any buffer layers to study the growth kinetics and epitaxial quality. PbSe was chosen as a representant of IV-VI materials, and layers were grown on (111)- and (100)-oriented silicon substrates.

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Fabrication of AlGaN/GaN HFET with a High Breakdown Voltage on 4-inch Si (111) Substrate by MOVPE

MRS Proceedings ◽

10.1557/proc-0955-i16-06 ◽

2006 ◽

Vol 955 ◽

Cited By ~ 2

Author(s):

Yuki Niiyama ◽

Sadahiro Kato ◽

Yoshihiro Sato ◽

Masayuki Iwami ◽

Jiang Li ◽

...

Keyword(s):

Buffer Layer ◽

Breakdown Voltage ◽

Field Effect Transistor ◽

Drain Current ◽

Growth Pressure ◽

Si Substrates ◽

Effect Transistor ◽

Gan Heterostructure ◽

Gan Film ◽

Gan Buffer Layer

ABSTRACTWe investigated an AlGaN/GaN heterostructure field effect transistor (HFET) on Si substrates using a multi-wafer metalorganic vapor phase epitaxy (MOVPE) system. It was confirmed that a GaN film with smooth surface and without any crack was obtained. To increase a resistance of a GaN buffer layer, the carbon (C) -doping was carried out by controlling the V/III ratio and the growth pressure. The breakdown voltage of the buffer layer was dramatically improved by introducing the C. As a result, the breakdown voltage was about 900 V when the C concentration was about ∼8×1018 cm−3. After while, an AlGaN/GaN heterojunction FET (HFET) on a C-doped GaN buffer layer was fabricated. We achieved the breakdown voltage of over 1000 V and the maximum drain current of over 150 mA/mm, respectively. It was found that the C doped buffer layer is very effective for improving the breakdown voltage of AlGaN/GaN HFETs.

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In Situ Investigation of the a-Si:H/C-Si Interface

MRS Proceedings ◽

10.1557/proc-420-449 ◽

1996 ◽

Vol 420 ◽

Author(s):

H. Feist ◽

C. Swiatkowski ◽

J. R. Elmiger ◽

M. Zipfel ◽

M. Kunst

Keyword(s):

Crystalline Silicon ◽

Microwave Frequency ◽

Ex Situ ◽

Silicon Substrates ◽

Si Substrates ◽

In Situ Investigation ◽

Drastic Increase ◽

Interface Recombination Velocity ◽

Recombination Velocity

AbstractThe deposition of a-Si:H films on crystalline silicon substrates was monitored in situ by transient photoconductivity measurements in the microwave frequency range. At the start of the deposition a drastic increase of the interface recombination velocity was observed, followed by a rapid decrease. The implications of these results for the structure of the interface are discussed. Changes of the interface after deposition were detected without a change of the temperature, even at 250'C: The long relaxation time of the structure of the interface will be discussed. Ex situ results on the samples produced will be compared to the in situ results in view of the passivation properties of a-Si:H films on c-Si substrates.

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Stress and Microstructure Evolution in Compositionally Graded Al1-xGaxN Buffer Layers for GaN Growth on Si

MRS Proceedings ◽

10.1557/proc-0892-ff02-02 ◽

2005 ◽

Vol 892 ◽

Cited By ~ 1

Author(s):

Xiaojun Weng ◽

Srinivasan Raghavan ◽

Elizabeth C Dickey ◽

Joan M Redwing

Keyword(s):

Buffer Layer ◽

Compressive Stress ◽

Microstructure Evolution ◽

Buffer Layers ◽

Threading Dislocation ◽

Cross Sectional ◽

Si Substrates ◽

Transmission Electron ◽

Dislocation Annihilation

AbstractWe have studied the evolution of stress and microstructure of compositionally graded Al1-xGaxN (0 ≤ x ≤1) buffer layers on (111) Si substrates with varying thicknesses. In-situ stress measurements reveal a tensile-to-compressive stress transition that occurs near the half-thickness in each buffer layer. Cross-sectional transmission electron microscopy (TEM) shows a significant reduction in threading dislocation (TD) density in the top half of the buffer layer, suggesting that the compressive stress enhances the threading dislocation annihilation. The composition of the buffer layers varies linearly with thickness, as determined by X-ray energy dispersive spectrometry (XEDS). The composition grading-induced compressive stress offsets the tensile stress introduced by microstructure evolution, thus yielding a tensile-to-compressive stress transition at x ≈ 0.5.

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Влияние ориентации кремниевой подложки с буферным подслоем карбида кремния на диэлектрические и полярные свойства пленок нитрида алюминия

Физика твердого тела ◽

10.21883/ftt.2019.12.48558.22ks ◽

2019 ◽

Vol 61 (12) ◽

pp. 2379

Author(s):

О.Н. Сергеева ◽

А.В. Солнышкин ◽

Д.А. Киселев ◽

Т.С. Ильина ◽

С.А. Кукушкин ◽

...

Keyword(s):

Thin Films ◽

Silicon Carbide ◽

Aluminum Nitride ◽

Buffer Layer ◽

Thin Layers ◽

Silicon Substrates ◽

Pyroelectric Effect ◽

Force Microscopy ◽

Piezoelectric Force Microscopy ◽

P Type

The dielectric and polar properties of thin films of aluminum nitride (AlN) epitaxially grown on variously oriented p-type silicon substrates with a buffer sublayer of silicon carbide (SiC), as well as on vicinal planes, are studied. According to the results of studies of the polar properties by two independent methods — the dynamic pyroelectric effect and piezoelectric force microscopy, it was shown that the use of a SiC buffer layer significantly improves the polar properties of thin layers of aluminum nitride.

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InGaN Thin Films Grown by ENABLE and MBE Techniques on Silicon Substrates

MRS Proceedings ◽

10.1557/proc-1068-c06-02 ◽

2008 ◽

Vol 1068 ◽

Cited By ~ 9

Author(s):

Lothar A. Reichertz ◽

Kin Man Yu ◽

Yi Cui ◽

Michael E Hawkridge ◽

Jeffrey W Beeman ◽

...

Keyword(s):

Composition Range ◽

Electrical Characterization ◽

Active Species ◽

Silicon Substrates ◽

Si Substrates ◽

Atom Flux ◽

Wide Range ◽

Theoretical Predictions ◽

Ingan Alloy ◽

P Type

ABSTRACTThe prospect of developing electronic and optoelectronic devices, including solar cells, that utilize the wide range of energy gaps of InGaN has led to a considerable research interest in the electronic and optical properties of InN and In-rich nitride alloys. Recently, significant progress has been achieved in the growth and doping of InGaN over the entire composition range. In this paper we present structural, optical, and electrical characterization results from InGaN films grown on Si (111) wafers. The films were grown over a large composition range by both molecular beam epitaxy (MBE) and the newly developed “energetic neutral atomic-beam lithography & epitaxy” (ENABLE) techniques. ENABLE utilizes a collimated beam of ∼2 eV nitrogen atoms as the active species which are reacted with thermally evaporated Ga and In metals. The technique provides a larger N atom flux compared to MBE and reduces the need for high substrate temperatures, making isothermal growth over the entire InGaN alloy composition range possible. Electrical characteristics of the junctions between n- and p-type InGaN films and n- and p-type Si substrates were measured and compared with theoretical predictions based on the band edge alignment between those two materials. The predicted existence of a low resistance tunnel junction between p-type Si and n-type InGaN was experimentally confirmed.

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GLANCING ANGLE REACTIVE PULSED LASER DEPOSITION (GRPLD) FOR Bi2O3/Si HETEROSTRUCTURE

Modern Physics Letters B ◽

10.1142/s0217984913501224 ◽

2013 ◽

Vol 27 (16) ◽

pp. 1350122 ◽

Cited By ~ 18

Author(s):

EVAN T. SALIM ◽

MARWA S. AL WAZNY ◽

MAKRAM A. FAKHRY

Keyword(s):

Crystalline Silicon ◽

Silicon Substrates ◽

In Situ Oxidation ◽

Current Voltage ◽

Glancing Angle ◽

Heterojunction Device ◽

Oxide Particles ◽

Current Voltage Characteristics ◽

P Type

Thin films of micro bismuth oxide particles were successfully prepared by in situ oxidation of the laser ablated bismuth metal. (111) oriented p-type crystalline silicon substrates were used. The effects of substrate tiled angle on the characteristics of the prepared film were studied. Also, the performance of n- Bi 2 O 3/p- Si heterojunction device was investigated. The obtained current–voltage characteristics in dark and under illumination insure the dependence of the fabricated device characteristic on the deposition angle. The I–V characteristics show that all prepared devices are of abrupt type.

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