Controlling electrode spacing by electro-deposition

Introduction

For an ongoing project in our group we are interested in placing two electrodes in close proximity to each other (50nm or less). However, with current cleanroom lithography techniques getting electrodes this close together can be a challenge. Perhaps the solution to the problem lies in an electrochemical approach. This is where electro-deposition comes in.

Electro-deposition

Electro-deposition, also known as Electroplating, is the process of adding a thin layer of metal to an existing metal structure. Electro-deposition takes place in an electrolyte which contains a solution of metal ions to be deposited. By applying the appropriate potentials to the electrodes, the metal ions in solution will start to attach to the existing electrodes, causing them to grow.

Figure 1: (a) Basic electro-deposition setup, an electrolyte containing ions which will be deposited on the electrodes at the bottom. (b) By applying a potential the ions will be deposited and the spacing between the electrodes will decrease.

Project Description

Investigate the electro-deposition process for growing gold electrodes to a narrow spacing

Goals:

·	Set up an electro-deposition experiment

·	Classify growth rate, smallest obtainable electrode spacing and accuracy of this process.

·	Explain these results using the theory behind electro-deposition

We offer:

·	Practical, hands-on experience.

·	Good support from the technicians of the BIOS-chair.

·	A practical assignment combined with theoretical work.

Contact

Maarten van Megen,

Email: m.j.j.vanmegen@ewi.utwente.nl

Phone: +31 (0)53 489 2755

Wouter Olthuis,

Email: w.olthuis@ewi.utwente.nl

Phone: +31 (0)53 489 2688