Fabrication of a high purity germanium double side strip detector by Pulsed Laser Melting doping

High-purity germanium detectors are the benchmark technology for high-resolution γ-ray spectroscopy. They are typically realized as reverse-biased diodes with a thick, fully depleted active region with a strong field to maximize the probability of γ-ray interaction. Their deployment in finely segmented planar architectures is limited by contact engineering, constraints on thermal-budget during fabrication and operation, and surface-related electric field management. Within the DIOMEDES project - financed by 5th committee of INFN - this thesis develops and validates a fabrication and characterisation workflow for planar double-sided strip detectors (DSSD) based on pulsed laser melting (PLM) doping, enabling shallow, thermally robust, easy to segment compatible with photolithographic segmentation. A p-type HPGe wafer (W1_p) is processed as a pathfinder device to qualify overall process integration and purpose-built tooling, while additional HPGe wafers and thicker crystals will be progressively brought into a largely common processing chain to assess scalability towards detector-grade geometries. In the adopted configuration the starting High purity crystal that is sightly p-type at operating temperature, is provided in our labs by the rectifying junction using Antimony (Sb) dopant precursor activated by PLM, whereas the opposite face implements a PLM-based p+ contact relying on an Al/Ge precursor. The process flow is designed as a modular and reproducible recipe, that is optimized and investigated in any step by specific tests and charachterization exploiting a multi-technique characterisation strategy including surface topography (AFM and stylus profilometry), chemical and dose verification (EDS and RBS), and eletrical transport measurements on dedicated test structures. The fabrication route -entirely conducted in the DFA and LNL labs- integrates surface preparation and planarisation, thin-film deposition, laser processing, metallisation, lithography, trenching to produce electrical separated contacts and passivation. The resulting workflow establishes a practical basis for lithium-free, segmented HPGe Double Side Strip Detector and provides a modular protocol to support subsequent electrical validation and fully segmented DSSD prototyping within DIOMEDES and related applications. A first fully processed segmented detector prototype was fabricated at the end of the experimental campaign, and its initial electrical characterisation is currently ongoing.