Low Temperature Silicon Epitaxy Grown by Electron-Beam Evaporation in an Ultra-High Vacuum System

1991 ◽  
Vol 237 ◽  
Author(s):  
Yung-Jen Lin ◽  
Tri-Rung Yew
Keyword(s):  
Electron Beam ◽  
Thermal Desorption ◽  
High Vacuum ◽  
High Energy ◽  
Electron Beam Evaporation ◽  
Ultra High Vacuum ◽  
Native Oxide ◽  
Vacuum System ◽  
Wafer Surface ◽  
Epitaxial Silicon

ABSTRACTThis paper presents the results of silicon epitaxial growth on silicon windows surrounded with oxide walls by electron-beam evaporation in an ultra-high vacuum system with a load-lock chamber. The wafer surface was in-situ cleaned in the growth chamber to remove native oxide by thermal desorption at about 840 °C and a base pressure of better than 2 × 10-9 Torr. The growth temperature was 200°C or higher. The pre-epitaxial silicon surface structure was inspected by reflection high energy electron diffraction (RHEED). The influence of the thermal desorption on the quality of the epi/substrate interface and epitaxial layers was studied. In addtion, the deposition parameters which control the epitaxial quality were investigated. The epitaxial films were characterized by cross-sectional trasmission electron microscopy (XTEM) and secondary ion mass spectroscopy (SIMS).

AlN thin films fabricated by ultra-high vacuum electron-beam evaporation with ammonia for silicon-on-insulator application

2005 ◽  
Vol 239 (3-4) ◽  
pp. 327-334 ◽  
Author(s):  
Ming Zhu ◽  
Peng Chen ◽  
Ricky K.Y. Fu ◽  
Weili Liu ◽  
Chenglu Lin ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Beam ◽  
High Vacuum ◽  
Electron Beam Evaporation ◽  
Silicon On Insulator ◽  
Ultra High Vacuum

Silicon Wafer Bonding: Effect of Wafer Surface Treatment on Interface Structure and Chemistry

2000 ◽  
Vol 6 (S2) ◽  
pp. 1074-1075
Author(s):  
M.J Cox ◽  
M.J. Kim ◽  
Hong Xu ◽  
R.W. Carpenter
Keyword(s):  
Wafer Bonding ◽  
High Vacuum ◽  
Interface Structure ◽  
Single Step ◽  
Ultra High Vacuum ◽  
Native Oxide ◽  
Wafer Surface ◽  
Step Process ◽  
Bonding Effect ◽  
Atomically Flat

The two most important characteristics of any surface considered for wafer bonding are cleanliness, surface smoothness and macroscopic flatness. Silicon wafers in the as-received condition have a native oxide on the surface several nanometers thick [1], Figure la shows that they also have a layer of hydrocarbons. While they are not clean, they are smooth. Our wafers were plasma or ion cleaned, chemically treated, and ultra high vacuum (UHV) thermal desorption annealed in different combinations to find the best method for providing smooth, contamination free substrates that will produce an atomically flat, chemically clean Si/Si bonded interface.The first approach was a single step process to remove the contaminants and then bond the clean wafers. Cleaning was accomplished by ion bombardment of the surface in an UHV chamber with base pressure 1x109 Torr. This ion cleaning chamber is connected between the UHV (2x10-10 ) bonding chamber and UHV (1x10-10) analysis chamber, allowing wafers to be cleaned, analyzed, and bonded without breaking vacuum [2].

Low Temperature In-Situ Processing for Si-MBE

1991 ◽  
Vol 220 ◽  
Author(s):  
Juergen Ramm ◽  
Eugen Beck ◽  
Albert Zueger
Keyword(s):  
Low Temperature ◽  
Hydrogen Plasma ◽  
Plasma Heating ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Native Oxide ◽  
Wafer Surface ◽  
Process Step ◽  
In Situ Processing

ABSTRACTA basic process sequence for low temperature in-situ processing of metal-insulator-semiconductor (MIS) structures in an ultra-high vacuum (UHV) multichamber system is presented. It includes conditioning of the process chamber by plasma heating, in-situ cleaning of silicon wafers, and conventional silicon molecular beam epitaxy (Si-MBE). The in-situ cleaning is achieved by an argon/hydrogen plasma treatment of the wafer surface at temperatures well below 400° C. The native oxide as well as carbon compounds are removed from the silicon surface. Etch rates for SiO2 are determined for various plasma parameters. Without additional cleaning procedures, silicon films are deposited in another process step using a quadrupole mass spectrometer controlled electron beam evaporator. Epitaxial films are obtained for substrate temperatures as low as 500°C on (100) and 600°C on (111) silicon for deposition rates of 0.05 nm/s.

Epitaxial Growth and Structure of Thin Single Crystal γ-Al2O3 Films on Si (111) Using e-Beam Evaporation of Sapphire in Ultra-High Vacuum

2004 ◽  
Vol 811 ◽  
Author(s):  
M. Hong ◽  
A. R. Kortan ◽  
J. Kwo ◽  
J. P. Mannaerts ◽  
S. Y. Wu
Keyword(s):  
Single Crystal ◽  
Epitaxial Growth ◽  
Substrate Surface ◽  
High Vacuum ◽  
High Energy ◽  
Electron Beam Evaporation ◽  
Ultra High Vacuum ◽  
Plane Component ◽  
High Structural Perfection ◽  
Single Crystal Sapphire

ABSTRACTWe have characterized the structure of epitaxial Al2O3 films deposited on Si (111) substrate using electron beam evaporation from a high-purity single crystal sapphire source in a molecular beam epitaxy (MBE) approach. The structural studies were carried out mainly by single crystal x-ray diffraction with the initial epitaxial growth observed by in-situ reflection high energy electron diffraction. The Al2O3 films grow in the cubic γ-phase with a very uniform thickness, and a high structural perfection. The <111> axes of the film and the Si substrate are well aligned. A mosaic scan of the Al2O3 (222) peak (with no in-plane component) finds a 0.3 degree (or 18') spread. All three unit cell vectors of the film and the substrate are parallel, but the in-plane cone scans of the {004} and {044} diffraction peaks about the surface normal find a ±3 degree film in-plane rotation with respect to the substrate surface orientation.

In-Process Diagnostic System for Semiconductor Materials Using UHV Wafer Transfer Chamber

1993 ◽  
Vol 324 ◽  
Author(s):  
F. Uchida ◽  
M. Matsui ◽  
H. Kakibayashi ◽  
M. Kouguchi ◽  
A. Mutoh ◽  
...  
Keyword(s):  
High Vacuum ◽  
Diagnostic System ◽  
Chemical Vapor ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
Wafer Surface ◽  
Measuring Instruments ◽  
Ion Pump ◽  
Semiconductor Wafer ◽  
Chemical Conditions

AbstractWe have developed a novel stand-alone diagnostic system that can analyze a semiconductor wafer surface in each process without introducing contamination. This allows us to analyze the relationship between chemical conditions and device properties.A UHV (Ultra High Vacuum) wafer transfer chamber is used between the measuring apparatus and the semiconductor processes. The chamber vacuum system, which consists of a battery driven ion pump and a liquid N2 shroud, achieves a pressure of 2 × 10−8 Pa (corresponding to about 100 min. until one monolayer of contamination has been adsorbed).Wafer transfer lines have been constructed between semiconductor vacuum processes, CVD (Chemical Vapor Deposition) and measuring instruments, ESCA (Electron Spectroscopy for Chemical Analysis) and TEM (Transmission Electron Microscope). Our results from ESCA and TEM showed measurements that carbon contamination and oxidation was suppressed.

Morphological Evolution During Ge/Si(100) Heteroepitaxy

1995 ◽  
Vol 399 ◽  
Author(s):  
Loren I. Espada ◽  
Sergio Chaparro ◽  
Jose Aguilar ◽  
Melissa Dorrance ◽  
Michael McKay ◽  
...  
Keyword(s):  
Driving Forces ◽  
Morphological Evolution ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Native Oxide ◽  
Vacuum System ◽  
Specimen Preparation ◽  
Size Distributions ◽  
Island Size ◽  
Plan View

ABSTRACTWe have investigated the morphological evolution of islanded Ge/Si(100) samples formed by > 3 monolayer (ML) Ge deposition. Ge was deposited onto Si(100) surfaces cleaned by flash desorption of the native oxide at rates near 1/2 ML per minute. Growths were performed in an ultra-high vacuum system with a base pressure of < 10−9 Torr. Substrate temperature during growth was 500 °C. Post-deposition processing ranged from no additional treatment to 1 hour at 560 °C anneals. Samples removed from the growth chamber were processed using standard transmission electron microscopy (TEM) specimen preparation techniques and characterized using plan-view TEM. Micrographs were computer analyzed to generate island size distributions (histograms of island size). These size distributions fall into general classes. First, samples with only coherent Ge islands exhibit relatively narrow size distributions. Secondly samples with both coherent and incoherent islands presented bi-modal size distributions with coherent islands populating the smaller radii. These results will be discussed in the context of a model which includes elastic as well as surface and interface energies as driving forces for ripening.

Hetero-Epitaxy of Group Va Metals on Sapphire

1972 ◽  
Vol 30 ◽  
pp. 492-493
Author(s):  
J. E. O'Neal ◽  
J. J. Bellina ◽  
B. B. Rath
Keyword(s):  
Thermal Contact ◽  
High Vacuum ◽  
Electron Beam Evaporation ◽  
Ultra High Vacuum ◽  
Backing Plate ◽  
Sapphire Substrates ◽  
Deposition Parameters ◽  
Polishing Damage ◽  
Reflection Electron Diffraction

Thin films of the bcc metals vanadium, niobium and tantalum were epitaxially grown on (0001) and sapphire substrates. Prior to deposition, the mechanical polishing damage on the substrates was removed by an in-situ etch. The metal films were deposited by electron-beam evaporation in ultra-high vacuum. The substrates were heated by thermal contact with an electron-bombarded backing plate. The deposition parameters are summarized in Table 1.The films were replicated and examined by electron microscopy and their crystallographic orientation and texture were determined by reflection electron diffraction. Verneuil-grown and Czochralskigrown sapphire substrates of both orientations were employed for each evaporation. The orientation of the metal deposit was not affected by either increasing the density of sub-grain boundaries by about a factor of ten or decreasing the deposition rate by a factor of two. The results on growth epitaxy are summarized in Tables 2 and 3.

A theory of contamination in electron microscopes by surface diffusion

1978 ◽  
Vol 36 (1) ◽  
pp. 116-117
Author(s):  
J.T. Fourie
Keyword(s):  
Electron Beam ◽  
Surface Diffusion ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Physical Parameters ◽  
Carbon Compounds ◽  
Hydrocarbon Molecules ◽  
Electron Microscopes ◽  
Primary Electrons ◽  
Long Chain

Contamination in electron microscopes can be a serious problem in STEM or in situations where a number of high resolution micrographs are required of the same area in TEM. In modern instruments the environment around the specimen can be made free of the hydrocarbon molecules, which are responsible for contamination, by means of either ultra-high vacuum or cryo-pumping techniques. However, these techniques are not effective against hydrocarbon molecules adsorbed on the specimen surface before or during its introduction into the microscope. The present paper is concerned with a theory of how certain physical parameters can influence the surface diffusion of these adsorbed molecules into the electron beam where they are deposited in the form of long chain carbon compounds by interaction with the primary electrons.

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

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