Two-contact Circular Test Structure for Determining Specific Contact Resistivity

2013 ◽  
Vol 1553 ◽  
Author(s):  
Y. Pan ◽  
G. K. Reeves ◽  
P. W. Leech ◽  
P. Tanner ◽  
A. S. Holland
Keyword(s):  
Ohmic Contacts ◽  
Electrical Characterization ◽  
Contact Resistivity ◽  
Test Structure ◽  
Metal Contacts ◽  
Circular Test ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
Analytical Expressions ◽  
Geometrical Dimensions

ABSTRACTAs ohmic contacts decrease in size and approach nanoscale dimensions, accurate electrical characterization is essential, requiring the development of suitable test structures for this task. We present here a new test structure derived from the standard three-contact circular transmission line model (CTLM) [1], for determining the specific contact resistivity of ohmic contacts. This test structure minimizes sources of error which arise from the CTLM by – (i) reducing the number of contacts within one test pattern from three to two, (ii) ensuring the assumption of equipotential metal contacts used in modelling is more easily attained experimentally, and (iii) allowing the fabrication of reduced geometrical dimensions essential for determining low specific contact resistivity values. The analytical expressions are presented and experiment results are undertaken to demonstrate the accuracy of the technique. There are no error corrections required for determining contact parameters using the presented test structure.

scholarly journals Using a two-contact circular test structure to determine the specific contact resistivity of contacts to bulk semiconductors

2015 ◽  
Vol 28 (3) ◽  
pp. 457-464
Author(s):  
Aaron Collins ◽  
Yue Pan ◽  
Anthony Holland
Keyword(s):  
Three Dimensional ◽  
Contact Resistivity ◽  
Test Structure ◽  
Contact Structures ◽  
Experimental Measurements ◽  
Circular Test ◽  
Bulk Semiconductors ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
P Type

We present a numerical method to extract specific contact resistivity (SCR) for three-dimensional (3-D) contact structures using a two-electrode test structure. This method was developed using Finite Element Modeling (FEM). Experimental measurements were performed for contacts of 200 nm nickel (Ni) to p+-type germanium (Ge) substrates and 200 nm of Titanium (Ti) on 4H-Silicon Carbide (SiC). The SCR obtained was (2.3-27)?10-6 ??cm2 for the Ni-Ge contacts and (1.3-2.4)?10-3 ??cm2 for the Ti-SiC.

A Microstructual Analysis of Au/Pd/Ti Ohmic Contacts for GaAs-Based Heterojunction Bipolar Transistors (HJBTs)

1991 ◽  
Vol 240 ◽  
Author(s):  
Bernard M. Henry ◽  
A. E. Staton-Bevan ◽  
V. K. M. Sharma ◽  
M. A. Crouch ◽  
S. S. Gill
Keyword(s):  
Structural Properties ◽  
Heterojunction Bipolar Transistors ◽  
Ohmic Contacts ◽  
Heat Treatments ◽  
Bipolar Transistors ◽  
Contact Resistivity ◽  
Base Region ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
Contact Resistivities

ABSTRACTAu/Pd/Ti and Au/Ti/Pd ohmic structures to thin p+-GaAs layers have been investigated for use as contacts to the base region of HJBTs. The Au/Pd/Ti contact system yielded specific contact resistivities at or above 2.8 × 10−5Ω:cm2. Heat treatments up to 8 minutes at 380°C caused only limited interaction between the metallization and the semiconductor. The metal penetrated to a maximum depth of ≃2nm. Specific contact resistivity values less than 10−5Ωcm2 were achieved using the Au/Ti/Pd (400/75/75nm) scheme. The nonalloyed Au/Ti/Pd contact showed the best combination of electrical and structural properties with a contact resistivity value of 9 × 10≃6Ωcm2 and Pd penetration of the GaAs epilayer to a depth of cs30nm.

Investigation of Cu-Ge/Gaas Metal-Semiconductor Interfaces for Low Resistance Ohmic Contacts

1996 ◽  
Vol 448 ◽  
Author(s):  
Serge Oktyabrsky ◽  
M.A. Borek ◽  
M.O. Aboelfotoh ◽  
J. Narayan
Keyword(s):  
Interfacial Layer ◽  
Ohmic Contacts ◽  
High Thermal Stability ◽  
Contact Resistivity ◽  
Polycrystalline Layer ◽  
Ohmic Behavior ◽  
Semiconductor Interfaces ◽  
Transmission Electron ◽  
Specific Contact ◽  
Specific Contact Resistivity

AbstractChemistry and interfacial reactions of the Cu-Ge alloyed ohmic contacts to n-GaAs with extremely low specific contact resistivity (6.5×10-7 Ω·cm2 for n~1017 cm-3) have been investigated by transmission electron microscopy, EDX and SIMS. Unique properties of the contact layers are related to the formation (at Ge concentration above 15 at.%) of a polycrystalline layer of ordered orthorhombic ε1-Cu3Ge phase. Formation of the ε1-phase is believed to be responsible for high thermal stability, interface sharpness and uniform chemical composition. The results suggest that the formation of the ζ- and ε1,-Cu3Ge phases creates a highly Ge-doped n+-GaAs interfacial layer which provides the low contact resistivity. Layers with Ge deficiency to form ζ-phase show nonuniform intermediate layer of hexagonal β-Cu3As phase which grows epitaxially on Ga{111} planes of GaAs. In this case, released Ga diffuses out and dissolves in the alloyed layer stabilizing the ζ-phase which is formed in the structures with average Ge concentration of as low as 5 at.%. These layers also exhibit ohmic behavior.

Cr/Ni/Au ohmic contacts to the moderately doped p- and n-GaN

1996 ◽  
Vol 449 ◽  
Author(s):  
Taek Kim ◽  
Myung C. Yoo ◽  
Taeil Kim
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Ohmic Contacts ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Contact Resistivity ◽  
Sapphire Substrates ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
Metalorganic Chemical

ABSTRACTWe report new Cr/Ni/Au and Ni/Cr/Au tri-layer metallization schemes for achieving low resistance ohmic contacts to moderately doped p- (∼1 × 1017/cm3), and n-GaN (∼1 × 1018/cm3) respectively. The metallizations were thermally evaporated on 2 μm-thick GaN layers grown on c-plane sapphire substrates by metalorganic chemical vapor deposition (MOCVD). Comparisons with bi-layer metallizations such as Ni/Au and Cr/Au were also made. The Cr/Ni/Au contacts showed a low specific contact resistivity of 9.1 × 10−5 Ω⋅cm2 to n-GaN while that of Ni/Cr/Au to p-GaN was 8.3 × 10−2 Ω⋅cm2. The Ni/Cr/Au contacts also showed a low specific contact resistivity of 2.6 × 10−4 Ω⋅cm2 to n-GaN. The Ni/Cr/Au metallization could made reasonable ohmic contacts to p- and n-GaN simultaneously

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