Pd deposition by Electrochemical ALD John L. Stickney, University of Georgia Research Foundation Inc, DMR 1006747

1. Pd deposition by Electrochemical ALDJohn L. Stickney, University of Georgia Research Foundation Inc, DMR 1006747 Pd nanofilms are of interest for their applications in catalysis, hydrogen storage, and technology. The control of deposition at the atomic layer scale is a challenge, presently being investigated using atomic layer deposition (ALD). ALD is based on the use of surface limited reactions to form deposits one atomic layer at a time. The result is a conformal deposit whose thickness is dependent on the number of deposition cycles performed. The PI works on the electrochemical variant of ALD (E-ALD), and has developed a cycle for the formation of Pd nanofilms. The majority of ALD is based on gas or vacuum phase work, and requires the use of volatile precursors to the elements of interest. The result is that organometallic compounds are used, and the organic parts tend to contaminate the deposits. In E-ALD, ultra pure salts can be used, and contamination avoided. Scheme for the electrodeposition of Pd films by ALD. The above Pd cycle is based on surface limited redox replacement (SLRR). An atomic layer of Cu is deposited, and then exchanged for one of Pd, the more stable element. This cycle can be repeated to form films of the desired thickness.

2. Scale up of Electrochemical ALDJohn L. Stickney, University of Georgia Research Foundation Inc, DMR 1006747 Electrochemical-ALD is the formation of deposits one atomic layer at a time using surface limited reactions. A wide range of materials have been grown using the method, including technologically important metals and semiconductors. Advantages of the method include the conformal deposition at or near room temperature. The PI has been approached concerning the growth of nanofilm materials over large substrate areas for a range of applications. Electrodeposition is known for the cost effective formation of thin film materials. Figure showing simulation of the fluid flow pattern through an electrochemical flow cell used for E-ALD. This design is referred to as a Z-cell, and is an initial design for scale up of the E-ALD process. Scale up is being pursued in answer to several proposed projects where conformal deposition over a large area is desired.