Improved geometrical design of the circular transmission line model ohmic contact test structure

Author(s):  
Aaron Collins ◽  
Yue Pan ◽  
Anthony Holland
2017 ◽  
Vol 30 (2) ◽  
pp. 257-265
Author(s):  
Neelu Shrestha ◽  
Geoffrey Reeves ◽  
Patrick Leech ◽  
Yue Pan ◽  
Anthony Holland

Contact test structures where there is more than one non-metal layer, are significantly more complex to analyse compared to when there is only one such layer like active silicon on an insulating substrate. Here, we use analytical models for complex test structures in a two contact test structure and compare the results obtained with those from Finite Element Models (FEM) of the same test structures. The analytical models are based on the transmission line model and the tri-layer transmission line model in particular, and do not include vertical voltage drops except for the interfaces. The comparison shows that analytical models for tri-layer contacts to dual active layers agree well with FEM when the Specific Contact Resistances (SCR) of the contact interfaces is a significant part of the total resistance. Overall, there is a broad range of typical dual-layer-to-TLTLM contacts where the analytical model works. The insight (and quantifying) that the analytical model gives on the effect of the presence of the contact, on the distribution of current away from the contact is shown.


1994 ◽  
Vol 337 ◽  
Author(s):  
Geoffrey K. Reeves ◽  
H. Barry Harrison

ABSTRACTThis paper briefly reviews the standard Transmission Line Model (TLM) commonly used to measure the specific contact resistance ρc and the sheet resistance Rsk beneath a planar ohmic contact. In the case of an alloyed ohmic contact, a more realistic three layer (Tri-Layer Transmission Line Model (TLTLM)) can be used for the analysis. This model is based on three layers (metal layer, alloyed semiconductor layer and the unalloyed semiconductor layer) and the two interfaces between them. By using appropriate TLTLM parameters, it is possible to calculate the sheet resistance Rsk that has been experimentally derived from the standard TLM. The new TLTLM model predicts that values of Rsk greater and less than Rsh (the unmodified epitaxial layer sheet resistance) are possible in agreement with experimentally reported observations.


2007 ◽  
Vol 101 (8) ◽  
pp. 086105 ◽  
Author(s):  
Yanjie Wang ◽  
Weixi Chen ◽  
Qiyuan Wei ◽  
Weihua Chen ◽  
Rui Li ◽  
...  

1993 ◽  
Vol 318 ◽  
Author(s):  
Geoffrey K. Reeves ◽  
Patrick W. Leech ◽  
H. Barry Harrison

ABSTRACTThis paper briefly reviews the standard Transmission Line Model (TLM) commonly used to measure the specific contact resistance of a planar ohmic contact. It is proposed that in the case of a typical Au-Ge-Ni alloyed ohmic contact, a more realistic model would need to take into account the presence of the alloyed layer at the metal-semiconductor interface. An alternative is described which is based on three contact layers and the two interfaces between them, thus forming a Tri-Layer Transmission Line Model (TLTLM). Expressions are given for the contact resistance Rc and the contact end resistance Re of this structure, together with a current division factor, f. Values for the parameters of this model are inferred from experimentally reported values of Rc and Re for two types of contact.


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