Measurement of the zinc oxide-molybdenum specific contact resistance for applications in Cu(In,Ga)Se2-technology

• Published in: Thin solid films Vol. 519; no. 21; pp. 7545 - 7548
• Main Authors: OERTEL, M, GÖTZ, S, CIESLAK, J, HAARSTRICH, J, METZNER, H, WESCH, W
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier 31-08-2011
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Contact; Contact resistance; Contact resistance, contact potential; Cross-disciplinary physics: materials science; rheology; Deposition; Deposition by sputtering; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Exact sciences and technology; Film thickness; Inhomogeneities; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Molybdenum; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Zinc; Zinc oxide; Gallium; Electrical conductivity; Indium selenides; Zinc additions; Molybdenum oxide; Contact resistance; Layer thickness; Molybdenum; CIGS; Copper selenides; Transmission lines; Specific contact resistance; Zinc oxide; Transmission line model; ZnO; Copper; Sputter deposition; Gallium selenides
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2010.12.183

We developed an improved measuring structure based on the transmission line model (TLM) which allows us to determine the specific contact resistance between rf-sputtered aluminum doped zinc oxide (ZnO:Al) and dc-sputtered molybdenum despite inhomogeneities in film thickness and conductivity which normally prevent an accurate determination of this value with the TLM. The improvement was achieved by an interchange between the contact and the conduction bar material to get a lower resistance of the conduction bar. Using this structure, the specific contact resistance is ascertained to be (1.37+/-0.14)10-5 Omega cm2. In addition, the effects of variations of certain sputter deposition parameters and their influence on the specific contact resistance are demonstrated. In particular, a small amount of oxygen in the sputter gas during the molybdenum sputter process remarkably increases the specific contact resistance.