WP2: Hard implantation Masking Fabrication & Testing

D2.1 – Deep RIE mask specifications

The technology supported by the LEEMONS project requires discontinuities in the nano-layer of amorphized silicon. The crystalline passages ensure that the electric carriers can indeed pass through it. To achieve discontinuous ion implantation, hard masks pierced with holes and made of crystalline silicon are used as kinds of sieve for ions. UBFC will use a technique called Deep Reactive Ion Etching for manufacturing these silicon masks. They are then mounted on a specific graphite holder that is embedded in the ion implantation chamber of the CEA léti. This innovative implantation process is more industrializable than the use of photolithography techniques which require several resist deposition and stripping steps. Its use to replace certain manufacturing steps of MOEMS (Micro-Opto-Electro-Mechanical Systems) is therefore investigated in parallel.
The document presents additional solutions to reduce the size of mask openings through the use of ultra-thin wafers or thermal oxidations. Square and round shaped designs as well as calibration patterns are presented. The first masks to be manufactured are then offered. Finally, the execution plan of the tasks and its associated schedule are given.

D2.2 – Stencil Printing mask Request for Proposal

In its initial phase, the project LEEMONS the project focuses on developing advanced masks for ion implantation. The first approach used Deep Reaction Ion Etching (DRIE) silicon masks, but these might prove too fragile and difficult to scale for future industrial applications. As a result, more robust alternatives, such as mesh masks made of fine metal wires and stencil printing masks created from chemically or laser-etched thin metal plates are explored. These alternatives offer better mechanical resistance and potentially enable finer openings.
A major challenge in this development is the strict contamination policies at CEA Leti, which restrict the use of most metals in ion implantation chambers. To address this, anodization and other coating techniques to make metal-based masks compliant with these regulations are investigated. The request for proposal that will be sent to possible suppliers is given in annex of the document.
One of the project's main technical objectives is to ensure that the masks can withstand mechanical stress while maintaining 5μm-wide openings. This will be verified through direct measurements and implantation tests. Achieving this level of precision will not only benefit the LEEMONS technology but could also have valuable applications in Micro-Opto-Electro-Mechanical Systems (MOEMS) manufacturing.