Optimization of SI-Wafer Cleaning and the use of Buffer-Layers for Epitaxial Growth of Sige-Layers by VLPCVD at T = 650 C

MRS Proceedings ◽

10.1557/proc-259-461 ◽

1992 ◽

Vol 259 ◽

Author(s):

Matty R. Caymax ◽

J. Poortmans ◽

A. Van Ammel ◽

W. Vandervorst ◽

J. Vanhellemont ◽

...

Keyword(s):

Low Temperature ◽

Epitaxial Growth ◽

Oxide Layer ◽

Layer Growth ◽

Buffer Layers ◽

Ex Situ ◽

Wafer Cleaning ◽

Dry Etch ◽

Water Rinse ◽

Si Wafer

ABSTRACTFor low-temperature epi-growth in UHV-CVD-systems, the pre-epi, ex-situ cleaning of Si-wafers is known to be very critical. Various ways of etching the chemical oxide-layer after RCA-cleaning have been analysed by SIMS-measurements of the interfacial C, 0 and Bcontamination. Layer growth was performed at 650 C under a flow of 20 sccm of silane at 0.26 Pa. The best results (C and 0 below 2 % of a monolayer, and no detectable amounts of B) were obtained with “dry” etch-procedures, i.e. in which no water-rinse was applied after a normal 2 % HF-dip, or where 1F-vapour was used instead. Growth of Si1-xGex-layers with x < 0.1 succeeds quite well on such prepared substrates; for x between 0.1 and 0.25, we have found the use of a thin, pure Si-buffer layer (150 Å) to be indispensable. For x > 0.25, the growing layer can become quite rough, although this varies in time.

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Nitrogen Plasma Pretreatment of Sapphire Substrates for the GaN Buffer Growth by Remote Plasma Enhanced MOCVD

MRS Proceedings ◽

10.1557/proc-449-53 ◽

1996 ◽

Vol 449 ◽

Cited By ~ 2

Author(s):

Min Hong Kim ◽

Cheolsoo Sone ◽

Jae Hyung Yi ◽

Soun Ok Heur ◽

Euijoon Yoon

Keyword(s):

Low Temperature ◽

Vapor Deposition ◽

Nitrogen Plasma ◽

Layer Growth ◽

Buffer Layers ◽

Rf Power ◽

Remote Plasma ◽

Sapphire Substrates ◽

Nucleation Sites ◽

Plasma Pretreatment

ABSTRACTLow-temperature GaN buffer layers with smooth surfaces and high crystallinity could be prepared by a remote plasma enhanced metalorganic vapor deposition after the pretreatment of substrates with rf nitrogen plasma. Smooth AIN thin layer was formed on the (0001) sapphire substrate by the nitrogen plasma pretreatment for an hour. The AIN layer provided the nucleation sites for the subsequent buffer layer growth, thus highly preferred (0001) GaN buffer layers could be grown on the pretreated substrate. Formation of the AIN layer on sapphire and the surface smoothness were affected by pretreatment parameters such as exposure time, temperature, and rf power.

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Process Steps for High Quality Si-Based Epitaxial Growth at Low Temperature via RPCVD

Materials ◽

10.3390/ma14133733 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3733

Author(s):

Jongwan Jung ◽

Baegmo Son ◽

Byungmin Kam ◽

Yong Sang Joh ◽

Woonyoung Jeong ◽

...

Keyword(s):

Low Temperature ◽

Epitaxial Growth ◽

Chemical Vapor ◽

Epitaxial Films ◽

Ex Situ ◽

High Quality ◽

Reduced Pressure ◽

Dry Cleaning ◽

Gaseous Environment

The key process steps for growing high-quality Si-based epitaxial films via reduced pressure chemical vapor deposition (RPCVD) are investigated herein. The quality of the epitaxial films is largely affected by the following steps in the epitaxy process: ex-situ cleaning, in-situ bake, and loading conditions such as the temperature and gaseous environment. With respect to ex-situ cleaning, dry cleaning is found to be more effective than wet cleaning in 1:200 dilute hydrofluoric acid (DHF), while wet cleaning in 1:30 DHF is the least effective. However, the best results of all are obtained via a combination of wet and dry cleaning. With respect to in-situ hydrogen bake in the presence of H2 gas, the level of impurities is gradually decreased as the temperature increases from 700 °C to a maximum of 850 °C, at which no peaks of O and F are observed. Further, the addition of a hydrogen chloride (HCl) bake step after the H2 bake results in effective in-situ bake even at temperatures as low as 700 °C. In addition, the effects of temperature and environment (vacuum or gas) at the time of loading the wafers into the process chamber are compared. Better quality epitaxial films are obtained when the samples are loaded into the process chamber at low temperature in a gaseous environment. These results indicate that the epitaxial conditions must be carefully tuned and controlled in order to achieve high-quality epitaxial growth.

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Effects of Low-Temperature GeSn Buffer Layers on Sn Surface Segregation During GeSn Epitaxial Growth

Electronic Materials Letters ◽

10.1007/s13391-019-00179-y ◽

2019 ◽

Vol 16 (1) ◽

pp. 9-13

Author(s):

Takahiro Tsukamoto ◽

Nobumitsu Hirose ◽

Akifumi Kasamatsu ◽

Toshiaki Matsui ◽

Yoshiyuki Suda

Keyword(s):

Low Temperature ◽

Epitaxial Growth ◽

Surface Segregation ◽

Buffer Layers

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Epitaxial growth of non-polar a-plane AlN films by low temperature sputtering using ZnO buffer layers

Thin Solid Films ◽

10.1016/j.tsf.2011.01.149 ◽

2011 ◽

Vol 519 (15) ◽

pp. 5090-5094 ◽

Cited By ~ 11

Author(s):

Hou-Guang Chen ◽

Sheng-Rui Jian ◽

Hui-Ling Kao ◽

Meei-Ru Chen ◽

Gou-Zhi Huang

Keyword(s):

Low Temperature ◽

Epitaxial Growth ◽

Buffer Layers

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Low temperature surface preparation of GaN substrates for atomic layer epitaxial growth: Assessment of ex situ preparations

Journal of Vacuum Science & Technology A Vacuum Surfaces and Films ◽

10.1116/1.5080090 ◽

2019 ◽

Vol 37 (2) ◽

pp. 020908 ◽

Cited By ~ 1

Author(s):

Samantha G. Rosenberg ◽

Daniel J. Pennachio ◽

Christa Wagenbach ◽

Scooter D. Johnson ◽

Neeraj Nepal ◽

...

Keyword(s):

Low Temperature ◽

Epitaxial Growth ◽

Surface Preparation ◽

Atomic Layer ◽

Ex Situ ◽

Growth Assessment ◽

Temperature Surface

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Low temperature epitaxial growth and characterization of Ga-doped ZnO thin films on Al2O3 (0001) substrates prepared with different buffer layers

Applied Surface Science ◽

10.1016/j.apsusc.2012.01.109 ◽

2012 ◽

Vol 258 (12) ◽

pp. 5073-5079 ◽

Cited By ~ 8

Author(s):

Seung Wook Shin ◽

G.L. Agawane ◽

In Young Kim ◽

Ye Bin Kwon ◽

In Ok Jung ◽

...

Keyword(s):

Thin Films ◽

Low Temperature ◽

Epitaxial Growth ◽

Buffer Layers ◽

Zno Thin Films ◽

Doped Zno

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Optimization of the GaN epilayer quality using in-situ reflectance measurements

MRS Proceedings ◽

10.1557/proc-639-g3.8 ◽

2000 ◽

Vol 639 ◽

Cited By ~ 2

Author(s):

Sandra Ruffenach-Clur ◽

Matthieu Moret ◽

Olivier Briot ◽

Nathanaël Moreaud ◽

Joseph Calas ◽

...

Keyword(s):

Low Temperature ◽

Growth Temperature ◽

Layer Growth ◽

Ex Situ ◽

Nucleation Layer ◽

Mocvd Growth ◽

System A ◽

Tremendous Amount ◽

Temperature Deposition

ABSTRACTAlthough a tremendous amount of work has been done these last years on the nitride semiconductor system, a lot is still to be understood regarding the growth mechanisms of GaN. The standard GaN MOCVD growth process includes the low temperature deposition of a nucleation layer, followed by an anneal at high temperature, and the GaN layer is then deposited. The number of process parameters which can be used to tune the growth is very large (temperatures, times, thicknesses, molar flow rates and ratios …) and, due to the coupling between them, the role of each one is not clearly understood. In this paper, we present systematic series of growth experiments, where in-situ reflectance monitoring was used and correlated to ex-situ optical characterization of the samples by photoluminescence at low temperature (2K). Here, we demonstrate that the nucleation layer and its annealing have a determining effect. The nucleation layer growth temperature was not found to be a very sensitive parameter, while the amount of re-crystallization is. Surprisingly, the amount of ammonia present in the gas phase has a determining effect on the recrystallization behavior of the nucleation layer. Another interesting point is the sensitivity versus growth temperature for the main GaN layer, which was found to affect the initial stages of the growth in a drastic manner when changed by only 5°C. In-situ reflectance allowed us to tune precisely our process and to obtain GaN layers with 500 cm2/Vs electron mobility at room temperature and photoluminescence fwhm of 1.7 meV at 2K for the donor-bound exciton.

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The Effect of Si Additions on the Epitaxial Growth of Gel−x Cx Alloys on Si(100)

MRS Proceedings ◽

10.1557/proc-440-371 ◽

1996 ◽

Vol 440 ◽

Cited By ~ 1

Author(s):

Bi-Ke Yang ◽

J. D. Weil ◽

M. Krishnamurthy

Keyword(s):

Epitaxial Growth ◽

Molecular Beam ◽

Layer Growth ◽

Ex Situ ◽

Growth Mechanisms ◽

X Ray Diffraction ◽

Planar Defects ◽

X Ray ◽

Transmission Electron

AbstractWe report on the differences in the epitaxial growth mechanisms between Ge1−xCx (O<x<0.1) and Ge1−x−ySixCy (x=0.2, 0<y<0.05) alloys grown on Si(100) using low temperature( 200°C) molecular beam epitaxy. Thin films (50˜65nm) were characterized in situ by RHEED and ex situ by transmission electron microscopy and x-ray diffraction. With increasing C concentration, the microstructure of both Ge and GeSi alloys changes from 2D layer growth to 3D islanding. The d400 spacing of the relaxed alloys decreases marginally, with a maximum of 1at.% C being substitutionally incorporated. Ge-C films with higher C content have a high density of planar defects, typically twins and stacking faults. The addition of 20% Si does not appear to increase the amount of substitutional C in the films. Rather, the additions of 20% Si to Ge-C alloys somehow seems to enhance the tendency for the formation of planar defects.

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