The Development of Solid Phase Regrowth on GaAs and its applications

1993 ◽  
Vol 319 ◽  
Author(s):  
L. C. Wang
Keyword(s):  
Ohmic Contacts ◽  
Solid Phase ◽  
Low Loss ◽  
Ohmic Behavior ◽  
Gaas Substrates ◽  
Layer Structures ◽  
Solid Phase Reactions ◽  
Solid Phase Regrowth ◽  
P Type ◽  
Ohmic Contact Formation

AbstractA solid phase regrowth process on GaAs has been observed in Pd- and Ni- based bi-layer structures, e.g. the Si/Ni, the Ge/Pd, the In/Pd, and the Sb/Pd structures. Due to the regrowth, uniform epitaxial layers of Ge, GaAs, InxGa1-xAs, and GaSbl-xAsx on GaAs substrates by solid phase reactions can achieved. The model of this regrowth process will be presented. Based on this regrowth mechanism, a series of non-spiking planar ohmic contacts on n and p type GaAs have been developed. Low contact resistivity in the range of mid 10−7 Ω-cm2 was obtained. The ohmic contact formation mechanism of these contacts will also be discussed. All the studies suggest that the ohmic behavior is a result of the formation of an n+ or p+ surface layer via solid phase reactions. The regrowth process has also been utilized to achieve compositional disordering of GaAs/AlGaAs superlattices, and low loss AlGaAs/GaAs waveguide has been obtained.

Solid-Phase Ohmic Contacts to GaAs with TiN Diffusion Barriers

1984 ◽  
Vol 37 ◽  
Author(s):  
H. P. Kattelus ◽  
J. L. Tandon ◽  
A. H. Hamdi ◽  
M-A. Nicolet
Keyword(s):  
Diffusion Barrier ◽  
Ohmic Contacts ◽  
Solid Phase ◽  
Diffusion Barriers ◽  
Thermally Stable ◽  
Ohmic Behavior ◽  
Tin Film ◽  
The Stability ◽  
P Type

AbstractWe report on contacts to p-type GaAs formed by a GaAs/Pt/TiN/Ag system. Ohmic behavior in this system is believed to be accomplished by the solidstate reaction of Pt with GaAs. This reaction is confined by the TiN film which is thermally stable. In addition, the TiN film acts as an excellent diffusion barrier in preventing the intermixing of the top Ag layer with GaAs or Pt. Contacts formed with such controlled reaction have important implications for the stability of shallow p-n junction devices.

Ohmic Contact Formation Mechanism in the Ge/Pd/N-GaAs System

1989 ◽  
Vol 148 ◽  
Author(s):  
E.D. Marshall ◽  
S.S. Lau ◽  
C.J. Palmstrøm ◽  
T. Sands ◽  
C.L. Schwartz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Solid Phase ◽  
Cross Sectional ◽  
Ohmic Behavior ◽  
Transmission Electron ◽  
Solid Phase Regrowth ◽  
Ohmic Contact Formation ◽  
Secondary Ion

ABSTRACTAnnealed Ge/Pd/n-GaAs samples utilizing substrates with superlattice marker layers have been analyzed using high resolution backside secondary ion mass spectrometry and cross-sectional transmission electron microscopy. Interfacial compositional and microstructural changes have been correlated with changes in contact resistivity. The onset of good ohmic behavior is correlated with the decomposition of an intermediate epitaxial Pd4(GaAs,Ge2) phase and solid-phase regrowth of Ge-incorporated GaAs followed by growth of a thin Ge epitaxial layer.

Ni/Si-Based Ohmic Contacts to p- and n-Type GaN

1997 ◽  
Vol 482 ◽  
Author(s):  
E. Kamińska ◽  
A. Piotrowska ◽  
A. Barcz ◽  
M. Guziewicz ◽  
S. Kasjaniuk ◽  
...  
Keyword(s):  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Solid Phase ◽  
Contact Region ◽  
Structural Transformations ◽  
Initial Reaction ◽  
Ohmic Behavior ◽  
Region I ◽  
Solid Phase Regrowth

AbstractNi/Si-based ohmic contact scheme for GaN, based on the solid-phase regrowth (SPR) mechanism have been developed. Using Mg and Si as dopant species, ohmic contacts with a resistivity of ∼1*10-3Ωcm2 to p-GaN (p≈3*1017 cm-3) and n-GaN (n≈2*1017cm-3), respectively, have been obtained. SIMS, XRD, and RBS analysis show in as-deposited contacts, an initial reaction at GaN/Ni interface, leading to the formation of an Ni-Ga-N layer. The ohmic behavior of contacts, observed after annealing at 400°C, is accompanied by structural transformations in the contact region: i) the decomposition of Ni-Ga-N layer and ii) the growth of NiSi compound.

Ohmic Contact Formation to Doped GaN

1995 ◽  
Vol 395 ◽  
Author(s):  
L. L. Smith ◽  
M. D. Bremser ◽  
E. P. Carlson ◽  
T. W. Weeks ◽  
Y. Huang ◽  
...  
Keyword(s):  
Ohmic Contact ◽  
Electron Beam Evaporation ◽  
Integrated Analysis ◽  
Cross Sectional ◽  
Contact Materials ◽  
Ohmic Behavior ◽  
Specific Contact ◽  
P Type ◽  
Ohmic Contact Formation ◽  
Contact Resistivities

ABSTRACTOhmic contact strategies for n- and p-type GaN have been investigated electrically, chemically, and microstructurally using transmission line measurements, high-resolution EELS and cross-sectional TEM, respectively. The contributions to contact performance from work function differences, carrier concentrations, annealing treatments, and interface metallurgy have been examined. The contact materials of Ti, TiN, Au, and Au/Mg were deposited via electron beam evaporation; Al was deposited via thermal evaporation. As-deposited Al and TiN contacts to highly doped n-GaN were ohmic, with room-temperature specific contact resistivities of 8.6×10−5 Ω cm2 and 2.5×10−5 Ωcm2 respectively. The Ti contacts developed low-resistivity ohmic behavior as a result of annealing; TiN contacts also improved with further heat treatment. For p-GaN, Au became ohmic with annealing, while Au/Mg contacts were ohmic in the as-deposited condition. The performance, structure, and composition of different contact schemes varied widely from system to system. An integrated analysis of the results of this study is presented below and coupled with a discussion of the most appropriate contact systems for both n- and p-type GaN.

Au Ohmic Contacts to P-Type Hg1-xCdxte Utilizing Thin Interfacial Layers

1990 ◽  
Vol 181 ◽  
Author(s):  
V. Krishnamurthy ◽  
A. Simmons ◽  
C. R. Helms
Keyword(s):  
Interfacial Layer ◽  
Ohmic Contacts ◽  
Interface State ◽  
State Density ◽  
Interface State Density ◽  
Interfacial Chemistry ◽  
Interfacial Layers ◽  
Ohmic Behavior ◽  
P Type ◽  
Thin Plasma

ABSTRACTOhmic behavior is observed in electroless Au contacts to p -type Hg1−xCdxTe. Our investigation of the interfacial chemistry of such contacts suggest that this ohmic behavior may be due to the presence of a Te,O, and CI layer. To verify this correlation with interfacial chemistry, thin plasma oxide layers were used in evaporated Au contacts. The annealed plasma oxidized contacts exhibited low contact resistances. This behavior was attributed to a low interface state density at the interfacial layer/Hg1−xCdxTe interface. In comparison, as-deposited and annealed Au contacts without a thin interfacial layer were rectifying with a large barrier height.

Planar, low‐loss optical waveguides fabricated by solid‐phase regrowth

1992 ◽  
Vol 61 (11) ◽  
pp. 1269-1271 ◽  
Author(s):  
W. Xia ◽  
L. S. Yu ◽  
Z. F. Guan ◽  
S. A. Pappert ◽  
P. K. L. Yu ◽  
...  
Keyword(s):  
Optical Waveguides ◽  
Solid Phase ◽  
Low Loss ◽  
Solid Phase Regrowth

Au/Ge/Pd Ohmic Contacts to n-TYPE InP

1992 ◽  
Vol 260 ◽  
Author(s):  
Ping Jian ◽  
Douglas G. Ivey ◽  
Robert Bruce ◽  
Gordon Knight
Keyword(s):  
Thermal Stability ◽  
Contact Resistance ◽  
Transmission Line ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microstructural Changes ◽  
Ohmic Behavior ◽  
Quaternary Phase ◽  
Transmission Line Method ◽  
Ohmic Contact Formation

ABSTRACTOhmic contact formation and thermal stability in a Au/Ge/Pd metallization to n-type InP, doped to a level of 1017 cm-3, have been investigated. Contact resistance was measured using a transmission line method, while microstructural changes were examined by means of TEM, EDX, CBED and SAD. Contacts became ohmic after annealing at temperatures ranging from 300°C to 375°C. A minimum contact resistance of 2.5×l0-6 Ω-cm2 was obtained after annealing at 350°C for 320s. The drop in resistance to ohmic behavior corresponded to the decomposition of an epitaxial quaternary phase (Au-Ge-Pd-P). Annealing at 400°C and above resulted in Au10In3 spiking into InP and a break down of contact lateral uniformity, which increased contact resistance.

A TEM Study of Cr Based Contacts to (0001) 6H-SiC

2000 ◽  
Vol 6 (S2) ◽  
pp. 1064-1065
Author(s):  
R.-J. Liu ◽  
M. J. Kim ◽  
R. W. Carpenter ◽  
L. M. Porter ◽  
L. P. Scheunemann ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Optoelectronic Devices ◽  
Wide Band ◽  
Electron Beam Evaporation ◽  
Rapid Thermal Anneal ◽  
Wide Band Gap ◽  
Ohmic Behavior ◽  
Transmission Electron ◽  
P Type ◽  
Sic Films

6H-SiC is a wide band-gap semiconductor. In recent years, a variety of high-power, -temperature, -speed and optoelectronic devices have been produced in SiC films. The search for metals which can form thermally stable, uniform ohmic contacts with SiC with low resistivity is still ongoing. In this study, Cr and CrBx (1<x<2) films were deposited by electron beam evaporation onto p-type, vicinal Si-terminated (0001) 6H-SiC surface. Both contacts exhibited rectifying behavior in the as-deposited condition. Ohmic-like behavior was observed for Cr/SiC system after annealing at 1000 °C for 240 seconds in a rapid thermal anneal furnace in an Ar atmosphere. It was also reported that ohmic behavior was observed for CrB2 /SiC system after annealing at 1100 °C for 2 minutes at a pressure of 5x10“7 Torr.2 The microstructure and chemistry of these two contact systems in both as-deposited and annealed conditions were investigated by transmission electron microscopy (TEM).

Sign in / Sign up

Export Citation Format

Share Document