Semiconductor doping process

The patented procedure is able to produce high doping junctions in semiconductors through an innovative process, alternative to ion implantation.

It is a cheap process, suitable for micro-/nanoelectronics and high-precision sensing applications.

How does it work?

The current techniques for doping semiconductors are afflicted by various problems that have limited their use, for example in nanoelectronics applications. Ionic implantation and subsequent heat treatment (annealing), besides having a considerable impact on costs, does not always lend itself to production processes.

This innovative process is instead able to create a high doping surface thanks to the application of laser melting to the sequence of deposits (protective film and source). While cooling after a laser pulsation, there is crystalline regrowth of the molten germanium and the transition to a coherent crystalline phase of the deposited protective film. This transformation makes it possible to control the thickness of the layer and the concentration of the dopant element in the contact, while protecting it from the atmosphere and limiting its diffusion outwards, through a cheaper process. A prototype of a hyper-pure germanium diode (HPGe) has been developed to apply this process over larger areas.

Applications

• Hyper-pure germanium (HPGe) radiation detectors;
• Semiconductor-based particle and/or radiation detectors;
• Microelectronics and nanoelectronics;
• Opto-electronic applications.

Advantages

• Reduced costs compared to the ionic system;
• High electrical activation;
• It preserves the purity of the underlying material;
• Applicable to a large number of dopants, including those sensitive to atmosphere;
• Elimination of dopant out-diffusion;
• Possibility of varying dopant concentration and contact thickness;
• Possibility to create ultra-shallow junctions.