Brief description of the ALD technology

The ALD technique builds new surfaces by exploiting self-limiting reactions between highly reactive gas molecules and active sites on surfaces. The self-limiting nature of the process ensures conformal and pin-hole free film on surfaces with complex geometries.  The principle behind the technique is to split a chemical reaction between two compounds into a sequential process, where each compound is allowed to saturate a substrate or support in an alternating manner. This strategy provides a digital control of thickness of the deposited material.

The layers are form in the following sequence:

1. Introduction and adsorption of precursor A to the surface.
2. Removal of the un-reacted precursor and reaction products.
3. Introduction and adsorption of precursor B to the surface.
4. Removal of the un-reacted precursor and reaction products via evacuation and/or inert gas flow.

Tool description

• The reactor chamber can accommodate samples up to 200 mm in diameter and 5 mm in height.
• Deposition Temperature: 100-300 °C
• Typical film thickness: 1 – 100 nm
• Typical deposition rates at 160 ºC for Al₂O₃ is ca. 1.2 Å/cycle. 
• Materials: Al₂O₃, TiO₂, HfO₂