The Application of Laser Annealing to the Fabrication of Impatt Diode Structures

1984 ◽  
Vol 35 ◽  
Author(s):  
Anthony E Adams ◽  
L A Hing
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Epitaxial Growth ◽  
Laser Processing ◽  
Laser Annealing ◽  
Boron Diffusion ◽  
Impatt Diode ◽  
Processing Techniques ◽  
P Type ◽  
Temperature Time

ABSTRACTThe conventional method for fabricating silicon IMPATT diode structures involves the epitaxial growth of successive n- and p-type layers onto a n+ substrate followed by a boron diffusion to form the final p+ layer. The high temperature time cycles experienced by the structure during these processes cause junction interfaces to become degraded through dopant diffusion. In this paper we examine the application of laser processing techniques to the epitaxial regrowth of low temperature deposited layers and report on the nature of the recrystallised material.

The Template Technique Applied to Epitaxial Growth of CrSi2 on Silicon (111)

1993 ◽  
Vol 317 ◽  
Author(s):  
John E. Manan ◽  
Robert G. Long ◽  
André Vantomme ◽  
Marc-A. Nicolet
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Low Temperature ◽  
Epitaxial Growth ◽  
Film Formation ◽  
The Other ◽  
High Temperature Annealing ◽  
Growth Technique ◽  
Reactive Deposition ◽  
Chromium Evaporation

ABSTRACTThe template growth technique was applied to the growth of CrSi2 thin films on Si(111) by UHV E-gun evaporation. A 4He+ channeling yield of -50% was obtained for an epitaxial -2100 Å-thick film of continuous morphology grown at 450° C The heteroepitaxial relationship is CrSi2 (001) / Si (lll) with CrSi2[210] ∥ Si<110>.In the case of film formation simply via reactive deposition epitaxy (RDE, chromium evaporation onto hot substrates) a severe crystallinity-Morphology tradeoff is always observed. Continuous films are formed at low temperature but no long-range epitaxy is found. On the other hand, high temperature annealing of these films induces the formation of islands that show good epitaxial alignment with the substrate. This tradeoff was addressed with the template growth technique.

4H-SiC PiN Diodes Fabricated Using Low-Temperature Halo-Carbon Epitaxial Growth Method

2010 ◽  
Vol 645-648 ◽  
pp. 925-928 ◽  
Author(s):  
Bharat Krishnan ◽  
Joseph Neil Merrett ◽  
Galyna Melnychuk ◽  
Yaroslav Koshka
Keyword(s):  
Low Temperature ◽  
Epitaxial Growth ◽  
Surface Passivation ◽  
Drift Region ◽  
Pin Diodes ◽  
Growth Technique ◽  
Growth Method ◽  
Heavily Doped ◽  
P Type

In this work, the benefits of the low-temperature halo-carbon epitaxial growth at 1300oC to form anodes of 4H-SiC PiN diodes were investigated. Regular-temperature epitaxial growth was used to form an 8.6 μm-thick n-type drift region with net donor concentration of 6.45x1015 cm-3. Trimethylaluminum doping, in situ during blanket low-temperature halo-carbon epitaxial growth, was used to form heavily doped p-type layers. Forward I-V characteristics measured from diodes having different anode areas indicated that the new epitaxial growth technique provides anodes with low values of the series resistance, even without contact annealing. At room temperature, a 100 μm-diameter diode had a forward voltage of 3.75 V at 1000A/cm² before annealing and 3.23 V after annealing for 2 min at 750°C. The reverse breakdown voltage was more than 680 V (on average) in the devices without edge termination or surface passivation.

Aluminum Doping by Low-Temperature Homoepitaxial Growth for Ni Ohmic Contacts to p-Type 4H-SiC

2009 ◽  
Vol 615-617 ◽  
pp. 581-584 ◽  
Author(s):  
Bharat Krishnan ◽  
Siva Prasad Kotamraju ◽  
Galyna Melnychuk ◽  
Neil Merrett ◽  
Yaroslav Koshka
Keyword(s):  
Low Temperature ◽  
Epitaxial Growth ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Metal Contacts ◽  
Atomic Concentration ◽  
Homoepitaxial Growth ◽  
Specific Contact ◽  
Sio2 Mask ◽  
P Type

Low-temperature halo-carbon homoepitaxial growth is suitable for selective epitaxial growth of 4H-SiC using SiO2 mask. A possibility of achieving high values of doping in combination with the selective growth makes it an alternative to ion implantation for selective doping in SiC. In this work, TMA doping in situ during a blanket low-temperature epitaxial growth was utilized to produce heavily Al doped SiC layers for Ohmic contact formation to p-type SiC. Nearly featureless epilayer morphology with Al atomic concentration exceeding 3x1020 cm-3 was obtained after growth at 13000C with the growth rate of 1.5 µm/hr. Ni TLM contacts with a thin adhesion layer of Ti were formed. The as-deposited metal contacts were almost completely Ohmic even before annealing. The specific contact resistance of 2x10-2 Ohm-cm2 and 6x10-5 Ohms-cm2 was achieved without and with contact annealing respectively. The resistivity of the epitaxial layers better than 0.01 Ohm cm was measured for Al atomic concentration of 2.7x1020 cm-3.

Some properties of flash-evaporated Ga1−xAsx films

1991 ◽  
Vol 69 (6) ◽  
pp. 738-742
Author(s):  
M. R. Harwood ◽  
D. E. Brodie
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Stoichiometric Ratio ◽  
Flash Evaporation ◽  
Glass Substrates ◽  
Seebeck Coefficients ◽  
Temperature Activation ◽  
Power Measurements ◽  
P Type ◽  
Excess Component

a-Ga1−xAsx films containing small GaAs crystallites were prepared by flash evaporation onto low-temperature glass substrates. The As content in the films was varied from 41 to 69 at.%. Thermoelectric power measurements indicate that Ga-rich films are n-type and As-rich films are p-type, but the Seebeck coefficients for samples near the stoichiometric ratio were too small to measure. The optical gaps vary with As content in a way that is consistent with the suggestion that the material appears to be an alloy of a-GaAs and the excess component. High-temperature activation energies place the Fermi level near midgap in all samples and this is in line with the suggestion that this class of materials tend to self compensate as the film grows.

Low Temperature Epitaxial Growth of High Temperature Superconductors:Bi-Sr-Ca-Cu-O.

1991 ◽  
Vol 222 ◽  
Author(s):  
Maki Kawai ◽  
Masami Mori ◽  
Shunji Watabe ◽  
Ziyuan Liu ◽  
Yasunori Tabira ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Substrate Temperature ◽  
Epitaxial Growth ◽  
Lattice Constant ◽  
Molecular Beam ◽  
Oxidation Process ◽  
Elementary Unit

ABSTRACTMolecular beam epitaxy of ultra thin films of Bi2Sr2CuO8-(2201 phase) is realized on the surface of SrTiO3 (100) and LaAlO3 (100) at the substrate temperature of 573 K, using 10-5Pa of NO2 as an oxidant. The film epitaxially grown from the surface of the substrate has identical in-plane lattice constant to the substrate itself. Such a growth can only be obtained on the substrate with similar lattice constant to those of the material to be formed. The crystallinity of the film strongly depended on the sequence of the metal depositions and the oxidation process. In the case of the Bi system, the elementary unit of the epitaxial growth has proved to be the subunit of the perovskite structure (Sr-Cu-Sr). The structure of the film grown on a substrate with large mismatch (MgO) is also discussed.

Comparison of Gate Oxide Processing Techniques for Thin Dielectric Films

1996 ◽  
Vol 446 ◽  
Author(s):  
Pat Schay ◽  
Fuyu Lin ◽  
Sergio Ajuria ◽  
John Stih
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Gate Dielectrics ◽  
Gate Oxide ◽  
Electrical Performance ◽  
Dielectric Films ◽  
Total Thickness ◽  
Large Area ◽  
Processing Techniques ◽  
Thin Dielectric Films

AbstractThis paper focuses on establishing a baseline for thin dielectric processes including: low temperature, dilute, stacked (TEOS), oxynitride, and high temperature annealed (grow‐anneal‐grow) oxidation. 105Å (total thickness) gate dielectrics were grown or deposited for this study. The stack oxide showed the highest Vbd yields for both large‐area and edge‐intensive capacitors, but the poorest Qbd. The N2O oxide yielded mediocre Vbd and Qbd. The low temperature and dilute oxides showed early breakdowns, but acceptable Qbd. 900°C thermal gate oxide showed slightly better average Vbd than low temperature and dilute oxides but comparable Qbd. The high temperature annealed oxide appears to have the best electrical performance, but the worst uniformity.

Structural Studies of GeTe-AgSbTe2 Alloys

2007 ◽  
Vol 1044 ◽  
Author(s):  
Alan Thompson ◽  
Jeff Sharp ◽  
C.J Rawn ◽  
B.C. Chackoumakos
Keyword(s):  
Crystal Structure ◽  
Phase Transformation ◽  
High Temperature ◽  
Low Temperature ◽  
Systematic Study ◽  
Structural Studies ◽  
Temperature Form ◽  
P Type ◽  
High Temperature Form ◽  
Important Constituent

AbstractGeTe, a small bandgap semiconductor that has native p-type defects due to Ge vacancies, is an important constituent in the thermoelectric material known as “TAGS” [1]. TAGS is an acronym for alloys of GeTe with AgSbTe2, and compositions are normally designated as TAGS-x, where x is the fraction of GeTe. TAGS-85 is the most important with regard to applications, and there also is commercial interest in TAGS-80. The crystal structure of GeTe1+δ has a composition-dependent phase transformation at a temperature ranging from 430°C (δ = 0) to ∼ 400°C (δ = 0.02) [2]. The high temperature form is cubic. The low temperature form is rhombohedral for δ < 0.01, as is the case for good thermoelectric performance. Addition of AgSbTe2 shifts the phase transformation to lower temperatures, and one of the goals of this work is a systematic study of the dependence of transformation temperature on the parameter x. We present results on phase transformations and associated instabilities in TAGS compositions in the range of 70-85 at.% GeTe.

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