Physical Vapor Deposition (PVD) is a collective set of processes used to deposit thin layers of material, typically in the range of few nanometers to several micrometers.1 PVD processes are environmentally friendly vacuum deposition techniques consisting of three fundamental steps (Figure 1):
Vaporization of the material from a solid source assisted by high temperature vacuum or gaseous plasma.
Transportation of the vapor in vacuum or partial vacuum to the substrate surface.
Condensation onto the substrate to generate thin films.
Different PVD technologies utilize the same three fundamental steps but differ in the methods used to generate and deposit material. The two most common PVD processes are thermal evaporation and sputtering. Thermal evaporation is a deposition technique that relies on vaporization of source material by heating the material using appropriate methods in vacuum. Sputtering is a plasma-assisted technique that creates a vapor from the source target through bombardment with accelerated gaseous ions (typically Argon). In both evaporation and sputtering, the resulting vapor phase is subsequently deposited onto the desired substrate through a condensation mechanism.2
Deposited films can span a range of chemical compositions based on the source material(s). Further compositions are accessible through reactive deposition processes. Relevant examples include co-deposition from multiple sources, reaction during the transportation stage by introducing a reactive gas (nitrogen, oxygen or simple hydrocarbon containing the desired reactant), and post-deposition modification through thermal or mechanical processing.3
PVD is used in a variety of applications, including fabrication of microelectronic devices, interconnects, battery and fuel cell electrodes, diffusion barriers, optical and conductive coatings, and surface modifications.4-6
Custom designed materials, including metal filled crucibles for Molecular Beam Epitaxy (MBE), are also available through our Hard Materials Center of Excellence. To inquire, please contact hardmaterials@sial.com.
Additional information about other vapor deposition techniques such as chemical vapor deposition (CVD) and atomic layer deposition (ALD) can be found in our CVD/ALD precursors spotlight.
References:
1. Powell, C. F.; Oxley, J. H. and Blocher Jr, J. M. Vapor Deposition; Wiley, New York, 1967. 2. Westwood, W. D. Sputter Deposition; AVS Education Committee book series, v. 2. New York: Education Committee, 2003. 3. Mattox, D. M. Handbook of Physical Vapor Deposition (PVD) Processing: Film Formation, Adhesion, Surface Preparation and Contamination Control; Noyes Publications, New Jersey,1998. 4. Geng, H. Semiconductor Manufacturing Handbook; McGraw-Hill: New York, 2004. 5. Helmersson, U.; Lattemann, M.; Bohlmark, J.; Ehiasarian, A. P.; Gudmundsson, J. T. Thin Solid Films, 2006, 513, 1. 6. Uhlenbruck, S.; Nedelec, R.; Sebold, D.; Buchkremer, H. P.; Stoever, D. ECS Transactions, 2011, 35, 2275.
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