Morphological Studies of Polysilicon Emitter Contacts

1984 ◽  
Vol 37 ◽  
Author(s):  
John C. Bravman ◽  
Gary L. Patton ◽  
Robert Sinclair ◽  
James D. Plummer
Keyword(s):  
High Temperature ◽  
Imaging Techniques ◽  
Single Crystal Silicon ◽  
High Temperature Annealing ◽  
Lattice Imaging ◽  
Crystal Silicon ◽  
Morphological Studies ◽  
Polysilicon Emitter ◽  
Free Interfaces ◽  
Silicon Interface

AbstractUsing high resolution lattice imaging techniques, the morphology of thepolycrystalline silicon - single crystal silicon interface has been correlated to (1) the surface treatment used prior to polysilicon deposition, (2) the polysilicon implant dose, and (3) high temperature annealing. Specimens which were chemically oxidized prior to deposition exhibited a continuous layer of amorphous oxide ≈1.5nm thick. High temperature annealing produces small discontinuities in this oxide which allow the polysilicon to make direct contact with, and become epitaxially aligned to, the substrate. Specimens which were etched in HF prior to deposition were characterized by nearly oxide-free interfaces, which, following implantation and annealing, exhibited regions of epitaxial realignment significantly larger than those found in the chemically oxidized films. Heavily implanted films annealed at high temperature displayed almost complete epitaxial realignment.

scholarly journals Влияние температуры отжига на электрически активные центры в кремнии, имплантированном ионами германия

2019 ◽  
Vol 53 (2) ◽  
pp. 161
Author(s):  
Н.А. Соболев ◽  
О.В. Александров ◽  
В.И. Сахаров ◽  
И.Т. Серенков ◽  
Е.И. Шек ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Annealing Temperature ◽  
Single Crystal Silicon ◽  
High Temperature Annealing ◽  
Crystal Silicon ◽  
Type Silicon ◽  
Special Distribution ◽  
P Type

AbstractThe implantation of Czochralski-grown p -type silicon with 1-MeV germanium ions at a dose of 2 . 5 × 10^14 cm^–2 does not lead to the amorphization of single-crystal silicon. Under subsequent high-temperature annealing, electrically active acceptor centers are transformed. Their concentration and special distribution depend on the annealing temperature. The possible factors determining how these centers are formed are discussed.

Processing Simox Wafer Below the Critical Temperature

1987 ◽  
Vol 107 ◽  
Author(s):  
Piran Sioshansi ◽  
Fereydoon Namavar
Keyword(s):  
High Temperature ◽  
Critical Temperature ◽  
Ion Implantation ◽  
Solid Phase ◽  
Single Crystal Silicon ◽  
High Temperature Annealing ◽  
Crystal Silicon ◽  
Oxygen Ion ◽  
Oxygen Ion Implantation ◽  
Multiple Step

AbstractThe creation of SIMOX material by multiple step substoichiometry oxygen ion implantation of silicon wafers followed by high temperature annealing has already been demonstrated by different groups [1-4] This paper reports on the formation of SIMOX wafers at temperatures well below the critical temperature (500-550°C) specified for oxygen implantation of the SIMOX process. A multiple step procedure has been devised, each step consisting of oxygen ion implantation at doses of 2.5 and 3 x 1017 O+/cm2 followed by solid phase epitaxy at a temperature of 950°C for two hours. Non-destructive optical analysis and XTEM investigation of the wafers indicates the formation of a continuous buried oxide with good quality single crystal silicon on the surface after accumulated dose of 1.1x1018 O+/cm2 following high temperature annealing at 1300°C for six hours.The processing of SIMOX material at a lower temperature will enable the utilization of a wide variety of ion implanters, will simplify the design of the end station of the new generation high current ion implanters, and will have an impact on the availability and economics of SIMOX wafers.

Silicon Carbide Die Attach Scheme for 500°C Operation

2000 ◽  
Vol 622 ◽  
Author(s):  
Liang-Yu Chen ◽  
Gary W. Hunter ◽  
Philip G. Neudeck
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Electrical Resistance ◽  
Room Temperature ◽  
Semiconductor Devices ◽  
Single Crystal Silicon ◽  
Film Material ◽  
Crystal Silicon ◽  
Pure Alumina ◽  
Die Attach

ABSTRACTSingle crystal silicon carbide (SiC) has such excellent physical, chemical, and electronic properties that SiC based semiconductor electronics can operate at temperatures in excess of 600°C well beyond the high temperature limit for Si based semiconductor devices. SiC semiconductor devices have been demonstrated to be operable at temperatures as high as 600°C, but only in a probe-station environment partially because suitable packaging technology for high temperature (500°C and beyond) devices is still in development. One of the core technologies necessary for high temperature electronic packaging is semiconductor die-attach with low and stable electrical resistance. This paper discusses a low resistance die-attach method and the results of testing carried out at both room temperature and 500°C in air. A 1 mm2 SiC Schottky diode die was attached to aluminum nitride (AlN) and 96% pure alumina ceramic substrates using precious metal based thick-film material. The attached test die using this scheme survived both electronically and mechanically performance and stability tests at 500°C in oxidizing environment of air for 550 hours. The upper limit of electrical resistance of the die-attach interface estimated by forward I-V curves of an attached diode before and during heat treatment indicated stable and low attach-resistance at both room-temperature and 500°C over the entire 550 hours test period. The future durability tests are also discussed.

scholarly journals A Constitutive Model for the Mechanical Behavior of Single Crystal Silicon at Elevated Temperature

2001 ◽  
Vol 687 ◽  
Author(s):  
H.-S. Moon ◽  
L. Anand ◽  
S. M. Spearing
Keyword(s):  
High Temperature ◽  
Constitutive Model ◽  
Single Crystal ◽  
Mechanical Behavior ◽  
Elevated Temperatures ◽  
Single Crystal Silicon ◽  
Operational Environment ◽  
Localized Deformation ◽  
Creep Tests ◽  
Crystal Silicon

AbstractSilicon in single crystal form has been the material of choice for the first demonstration of the MIT microengine project. However, because it has a relatively low melting temperature, silicon is not an ideal material for the intended operational environment of high temperature and stress. In addition, preliminary work indicates that single crystal silicon has a tendency to undergo localized deformation by slip band formation. Thus it is critical to obtain a better understanding of the mechanical behavior of this material at elevated temperatures in order to properly exploit its capabilities as a structural material. Creep tests in simple compression with n-type single crystal silicon, with low initial dislocation density, were conducted over a temperature range of 900 K to 1200 K and a stress range of 10 MPa to 120 MPa. The compression specimens were machined such that the multi-slip <100> or <111> orientations were coincident with the compression axis. The creep tests reveal that response can be delineated into two broad regimes: (a) in the first regime rapid dislocation multiplication is responsible for accelerating creep rates, and (b) in the second regime an increasing resistance to dislocation motion is responsible for the decelerating creep rates, as is typically observed for creep in metals. An isotropic elasto-viscoplastic constitutive model that accounts for these two mechanisms has been developed in support of the design of the high temperature turbine structure of the MIT microengine.

Non Destructive Determination of the Threading Dislocation Density of Smooth Simox Substrates using Atomic Force Microscopy

2000 ◽  
Vol 6 (S2) ◽  
pp. 1088-1089
Author(s):  
A. Domenicucci ◽  
R. Murphy ◽  
D. Sadanna ◽  
S. Klepeis
Keyword(s):  
Atomic Force Microscopy ◽  
High Temperature ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
High Dose ◽  
Threading Dislocation ◽  
Crystal Silicon ◽  
Force Microscopy ◽  
Atomic Force ◽  
High Temperature Anneal

Atomic force microscopy (AFM) has been used extensively in recent years to study the topographic nature of surfaces in the nanometer range. Its high resolution and ability to be automated have made it an indispensable tool in semiconductor fabrication. Traditionally, AFM has been used to monitor the surface roughness of substrates fabricated by separation by implanted oxygen (SIMOX) processes. It was during such monitoring that a novel use of AFM was uncovered.A SIMOX process requires two basic steps - a high dose oxygen ion implantation (1017 to 1018 cm-3) followed by a high temperature anneal (>1200°C). The result of these processes is to form a buried oxide layer which isolates a top single crystal silicon layer from the underlying substrate. Pairs of threading dislocations can form in the top silicon layer during the high temperature anneal as a result of damage caused during the high dose oxygen implant.

Deposition & Characterization of TiAlON & TiMoAlON Solar Absorber Coatings for High Temperature Photothermal Applications Prepared by PEM Controlled Dual-Gas Reactive Magnetron Sputtering

2012 ◽  
Vol 538-541 ◽  
pp. 344-349 ◽  
Author(s):  
Hai Bin Geng ◽  
Tao Wu ◽  
Cheng Wei Ma
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Near Infrared ◽  
Solar Spectrum ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Precise Control ◽  
Silicon Chips ◽  
Solar Absorber ◽  
Absorbing Layer

A novel Plasma Emission Monitoring (PEM) controlled N2-O2 dual gas reactive dcMS method is proposed for deopsiting TiAlON and TiMoAlON solar absorber coatings. Working in a 'cheated' feedback mode, the PEM controller ensures smooth & precise control of O/N ratio in obtained oxy-nitrides without occuring of serious target poisoning. The coatings have three functional layers including the infrared reflector, the absorbing layer, and the antireflection layer. The absorbing layers of the two kinds of coatings are both designed to have a gradually change Al and/or O content. However, the TiAlON coatings have a single TiAlON absorber layer while the TiMoAlON have a tandem absorber composed of a Mo doped TiAlN layer and a Mo doped TiAlON layer. Single-crystal silicon chips and glass slides are used as substrates to deposit the coatings and to characterize the photothermal conversion properties and thermal stability of the coatings by using SEM, UV-visible-near infrared photospectrometer, and solar spectrum emissiometer. The experimtal results show that the tandem TiMoAlON coating exhibits superior theraml stability up to 550oC. After annealing in air at 500oC for 8hrs, it exhibits higher absorptance than as-deposited status. The annealed TiMoAlON coating has a broad absorbing peak covering 400-800nm, which is beneficial to collect the majority energy in solar radiation. Due to its higher absorptivity and lower normal emissivity than the TiAlON coatings, the TiMoAlON coating yields a high solar selectivity (α/ε≈19) at room temperature. However, at 500oC, its ε value increases from 0.05 to about 0.25 which might attribute to its excessive thicknesses of the sublayers. The above results demonstrate that the proposed method is a convenient way for preparing high performance oxy-nitride solar absorber coatings which are suitable for non-vacuum high temperature photothermal applications.

Silicon Carbide: Progress in Crystal Growth

1987 ◽  
Vol 97 ◽  
Author(s):  
J. Anthony Powell
Keyword(s):  
Silicon Carbide ◽  
Crystal Growth ◽  
High Temperature ◽  
Epitaxial Growth ◽  
Recent Progress ◽  
Single Crystal Silicon ◽  
Silicon Substrates ◽  
Large Area ◽  
High Quality ◽  
Crystal Silicon

ABSTRACTSilicon carbide (SiC), with a favorable combination of semiconducting and refractory properties, has long been a candidate for high temperature semiconductor applications. Research on processes for producing the needed large-area high quality single crystals has proceeded sporadically for many years. Two characteristics of SiC have aggravated the problem of its crystal growth. First, it cannot be melted at any reasonable pressure, and second, it forms many different crystalline structures, called polytypes. Recent progress in the development of two crystal growth processes will be described. These processes are the modified Lely process for the growth of the alpha polytypes (e.g. 6H SiC), and a process for the epitaxial growth of the beta polytype (i.e. 3C or cubic SiC) on single crystal silicon substrates. A discussion of the semiconducting qualities of crystals grown by various techniques will also be included.

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