Selective Area Deposition of Passivants, Insulators, and Epitaxial Films of II-VI Compound Semiconductors

ABSTRACTII-VI semiconductor surface passivants, insulators, and epitaxial films have been deposited onto selective surface areas by employing a new masking and lift-off technique. The II-VI layers were grown by either conventional or photoassisted molecular beam epitaxy (MBE). CdTe has been selectively deposited onto HgCdTe epitaxial layers as a surface passivant. Selective-area deposition of ZnS has been used in metal-insulator-semiconductor (MIS) structures. Low resistance ohmic contacts to p-type CdTe:As have also been realized through the use of selectively-placed thin films of the semi-metal HgTe followed by a thermal evaporation of In. Epitaxial layers of HgTe, HgCdTe, and HgTe-CdTe superlattices have also been grown in selective areas on CdZnTe substrates, exhibiting specular morphologies and double-crystal x-ray diffraction rocking curves (DCXD) with full widths at half maximum (FWHMs) as narrow as 140 arcseconds.

Download Full-text

Comparison between Ni-SALICIDE and Self-Aligned Lift-Off Used in Fabrication of Ohmic Contacts for SiC Power MOSFET

Materials Science Forum ◽

10.4028/www.scientific.net/msf.963.490 ◽

2019 ◽

Vol 963 ◽

pp. 490-493

Author(s):

Tomasz Sledziewski ◽

Tobias Erlbacher ◽

Anton Bauer ◽

Lothar Frey ◽

Xi Ming Chen ◽

...

Keyword(s):

Electrical Properties ◽

Silicon Dioxide ◽

Ohmic Contacts ◽

Positive Impact ◽

Specific Resistance ◽

Power Mosfet ◽

Interlayer Dielectric ◽

Lift Off ◽

P Type

A comparison between self-aligned process (using lift-off) and Ni-SALICIDE used in fabrication of ohmic contacts for SiC Power MOSFET is done. Both processes are demonstrated for 3.3 kV SiC VDMOS transistors fabricated on 100 mm substrates. It is shown that the Ni-SALICIDE process with first silicidation at 500 °C does not degrade the electrical properties of silicon dioxide; particularly, a degradation of the interlayer dielectric between source and gate is not evident. Additionally, this first silicidation is found to have a positive impact on the specific resistance of contacts formed on p-type SiC using NiAl2.6% as an ohmic metal.

Download Full-text

Electrical characteristics and structural properties of ohmic contacts to p-type 4H-SiC epitaxial layers

Semiconductors ◽

10.1134/1.1187850 ◽

1999 ◽

Vol 33 (11) ◽

pp. 1206-1211 ◽

Cited By ~ 12

Author(s):

K. V. Vasilevskii ◽

S. V. Rendakova ◽

I. P. Nikitina ◽

A. I. Babanin ◽

A. N. Andreev ◽

...

Keyword(s):

Structural Properties ◽

Ohmic Contacts ◽

Epitaxial Layers ◽

Electrical Characteristics ◽

P Type

Download Full-text

Study of Ohmic Contacts on P-Type ZnSe and ZnSe Epitaxial Layers Grown by Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-281-727 ◽

1992 ◽

Vol 281 ◽

Author(s):

C. Piskoti ◽

B. Mykolajenko ◽

M. Vaziri

Keyword(s):

Molecular Beam Epitaxy ◽

Ohmic Contact ◽

Ohmic Contacts ◽

Molecular Beam ◽

Metal Contact ◽

Epitaxial Layers ◽

Preliminary Results ◽

Current Voltage ◽

Current Voltage Characteristics ◽

P Type

ABSTRACTTo study the formation of ohmic contacts, several metals have been deposited on p-types ZnTe and ZnSe epitaxial layers. The metals were deposited on the layers either by simple evaporation or by electroplating. The current-voltage characteristics associated with each metal contact were measured. The preliminary results of these measurements indicate that electroplating is a better technique for making ohmic contact to these layers.

Download Full-text

The formation and structure of Pd2InP on InP

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176745 ◽

1990 ◽

Vol 48 (4) ◽

pp. 722-723

Author(s):

Douglas G. Ivey ◽

Lin Zhang ◽

Ping Jian

Keyword(s):

Low Temperatures ◽

Ohmic Contacts ◽

Ternary Phase ◽

Semiconductor Surface ◽

Valuable Component ◽

Ternary Compounds ◽

Type Iii ◽

Annealing Conditions ◽

Dopant Incorporation ◽

P Type

Palladium appears to be an important component in contact metallizations to p-type III-V semiconductors. Several successful ohmic contacts containing Pd have been fabricated to p-type GaAs; e.g. Au/Pd/Zn/Pd to GaAs. Palladium is easily deposited on and reacts readily with GaAs, at relatively low temperatures, to form binary and ternary compounds. The formation of these compounds helps generate Ga vacancies in GaAs, necessary for dopant incorporation. Palladium also aids in the wetting of metals, such as Zn to GaAs, improving their adherance to the semiconductor surface. For the same reasons expressed above, Pd may also prove to be a valuable component in contact metallizations to p- type InP. Very little work has been done on the interaction between Pd and InP, however. Krishnan et al have reported on the formation of a Pd InP ternary phase, which is predominantly amorphous with some signs of crystallinity. The interaction between Pd and InP, under annealing conditions usually encountered in contact fabrication, is discussed in this paper. Particular emphasis is put on one ternary phase that forms during annealing, i.e Pd2InP.

Download Full-text

Ni∕Au Ohmic contacts to p-type Mg-doped CuCrO2 epitaxial layers

Applied Physics Letters ◽

10.1063/1.2719150 ◽

2007 ◽

Vol 90 (14) ◽

pp. 142101 ◽

Cited By ~ 15

Author(s):

W. T. Lim ◽

L. Stafford ◽

P. W. Sadik ◽

D. P. Norton ◽

S. J. Pearton ◽

...

Keyword(s):

Ohmic Contacts ◽

Epitaxial Layers ◽

P Type ◽

Mg Doped

Download Full-text

Investigations on Ni-Ti-Al Ohmic Contacts Obtained on P-Type 4H-SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.711.169 ◽

2012 ◽

Vol 711 ◽

pp. 169-173 ◽

Cited By ~ 7

Author(s):

Farah Laariedh ◽

Mihai Lazar ◽

Pierre Cremillieu ◽

Jean Louis Leclercq ◽

Dominique Planson

Keyword(s):

Ohmic Contacts ◽

Secondary Ion Mass Spectrometry ◽

Rapid Heating ◽

Specific Contact Resistance ◽

Transfer Length ◽

Current Voltage ◽

Before And After ◽

Specific Contact ◽

Lift Off ◽

P Type

Transfer Length Method (TLM) based-structures were fabricated on 0.8 µm-thick epitaxial p-type Silicon Carbide (4H-SiC) layers. TLM mesas were defined by a 2 µm height using an SF6/O2 reactive ion etching. TLM metal patterns were obtained by a lift-off procedure and electron beam deposition of Ni, Ti, Al and Pt. The patterned samples were annealed in Argon ambient at temperature ranging from 700°C up to 1000°C in a RTA furnace with a rapid heating ramp (up to 50°C/s) to complete the ohmic contact with the p-type SiC layer. Specific contact resistances were extracted from current/voltage measurements. To identify and follow the profile evolution of constituting element in the contacts and at the SiC/contact interface, the ohmic contacts were characterized using Secondary Ion Mass Spectrometry and Energy-Dispersive X-Ray spectroscopy before and after annealing. Ohmic contacts are obtained only for the Ni/Ti/Al and Ni/Ti/Al/Ni stacking layers and not for the Ti/Al/Ti/Ni and Ti/Al/Ti/Pt/Ni compositions. The specific contact resistance of Ni/Ti/Al/Ni stacking layers was observed to decrease from 2.7×10-4 Ω.cm2 at 700°C and 6.3×10-5 Ω.cm2 at 750°C to a minimal value of 1.5×10-5 Ω.cm2 at 800°C. Ohmic contacts are obtained with a reproducibility of 80 %.

Download Full-text

Thermodynamics and Microstructure Development in the Thin Film Reaction of Aluminum on Silicon Carbide

MRS Proceedings ◽

10.1557/proc-403-489 ◽

1995 ◽

Vol 403 ◽

Cited By ~ 1

Author(s):

T. S. Hayes ◽

F. T. Ray ◽

K. P. Trumble ◽

E. P. Kvam

Keyword(s):

Thin Film ◽

Thin Films ◽

Silicon Carbide ◽

Ohmic Contacts ◽

Microstructure Development ◽

P Type ◽

Microstructural Studies

AbstractA refined thernodynamic analysis of the reaction between molen Al and SiC is presented. The calculations indicate much higher Si concentrations for saturation with respect to AkC 3 formation than previously reported. Preliminary microstructural studies confirm the formation of interfacial A14C3 for pure Al thin films on SiC reacted at 9000C. The implications of the calculations and experimental observations for the production of ohmic contacts to p-type SiC are discussed.

Download Full-text

Correlation between the electrical properties and the interfacial microstructures of TiAl-based ohmic contacts to p-type 4H-SiC

Journal of Electronic Materials ◽

10.1007/s11664-004-0203-x ◽

2004 ◽

Vol 33 (5) ◽

pp. 460-466 ◽

Cited By ~ 50

Author(s):

S. Tsukimoto ◽

K. Nitta ◽

T. Sakai ◽

M. Moriyama ◽

Masanori Murakami

Keyword(s):

Electrical Properties ◽

Ohmic Contacts ◽

P Type

Download Full-text

Improvement of the Specific Contact Resistance on P-Type 4H-SiC by Using a Highly P-Typed Doped 4H-SiC Layer Selectively Grown by VLS Transport

Materials Science Forum ◽

10.4028/www.scientific.net/msf.806.57 ◽

2014 ◽

Vol 806 ◽

pp. 57-60

Author(s):

Nicolas Thierry-Jebali ◽

Arthur Vo-Ha ◽

Davy Carole ◽

Mihai Lazar ◽

Gabriel Ferro ◽

...

Keyword(s):

Contact Resistance ◽

Ohmic Contacts ◽

Schottky Barrier Height ◽

Annealing Temperature ◽

Process Condition ◽

Specific Contact Resistance ◽

High Doping Level ◽

Annealing Temperatures ◽

Specific Contact ◽

P Type

This work reports on the improvement of ohmic contacts made on heavily p-type doped 4H-SiC epitaxial layer selectively grown by Vapor-Liquid-Solid (VLS) transport. Even before any annealing process, the contact is ohmic. This behavior can be explained by the high doping level of the VLS layer (Al concentration > 1020 cm-3) as characterized by SIMS profiling. Upon variation of annealing temperatures, a minimum value of the Specific Contact Resistance (SCR) down to 1.3x10-6 Ω.cm2 has been obtained for both 500 °C and 800 °C annealing temperature. However, a large variation of the SCR was observed for a same process condition. This variation is mainly attributed to a variation of the Schottky Barrier Height.

Download Full-text