Differential Hall profiling of ultra-shallow junctions in Si and SOI

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Vol. 124; pp. 305 - 309
• Main Authors: Bennett, N.S., Smith, A.J., Colombeau, B., Gwilliam, R., Cowern, N.E.B., Sealy, B.J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05-12-2005
• Subjects: Differential Hall measurement; SOI; Ultra-shallow junctions; SOI; Differential Hall measurement; Ultra-shallow junctions
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2005.08.020

Determining the electrical characteristics of doped layers is a key challenge in understanding the success of the ion implantation and an anneal process. Hall measurements have the ability to measure the electrical activation and the carrier mobility. Differential Hall measurement (DHM) is one method capable of determining these electrical properties as a function of depth. Unlike spreading resistance profiling (SRP), this technique can measure the active carrier profile without any assumption on the magnitude of the mobility.
In this paper, we demonstrate a novel DHM technique to profile ultra-shallow junctions down to ∼15
nm using a native oxide removal process. This technique is shown to profile p- and n-type layers with nm depth resolution.
Results for mobility values as a function of carrier concentration for different experimental conditions provide important data for accurate modelling of junction behaviour.
Finally, we show how to optimise the technique parameters to overcome some of the inherent difficulties that are associated with DHM profiling such as layer removal uniformity, profile distortion due to surface states, and limited depth resolution.