Introduction

This patented procedure allows the creation of highly doped junctions in semiconductors through an innovative process, alternative to ion implantation. It is more convenient and suitable for micro/nanoelectronics and for highly sensitive detectors.

Technical features

Current semiconductor doping techniques have several difficulties and limitations for example in microelectronic applications. Ion implantation and consequent laser annealing are not always compatible with production processes and have a strong impact on costs. This innovative semiconductor doping process can create a highly doped surface layer thanks to the application of laser melting on the deposited layers (source and protective layers). During the cooling that follows the laser pulse, there is a crystalline regrowth of molten germanium and a transition to a coherent crystalline phase of the deposited protective film. This transformation can control the thickness of the layer and the concentration of the doping element in the contact, protecting it at the same time from the atmosphere and limiting its out-diffusion, through this less expensive process.

A prototype of a hyper pure germanium diode (HPGe) has been developed to apply this process on larger areas. Current TRL is 5.

Possible Applications

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

Advantages

• Less expensive compared to ion implantation;
• Elevated electrical activation;
• Preserves the purity of the underlying material;
• Applicable to a large number of dopants, including those sensitive to the atmosphere;
• Eliminates dopant out-diffusion;
• Applicable to a wide range of dopant concentration and contact thickness;
• Suitable for ultrashallow junctions.