PhD: Atomic-layer etching of diamond (M/F)

Job Description

Thesis Subject

Diamond is the ultimate semiconductor. High-power devices fabricated using diamond technology demonstrate its potential for energy conversion applications, such as the 3-kilovolt transistor reported by the NEEL Institute. However, its exceptional physical properties also make the technology more challenging, particularly the etching process. Diamond is inert to all chemical mixtures at room temperature. The most effective method involves using inductively coupled plasma reactive ion etching (ICP-RIE) with an oxygen-containing gas mixture, but this also induces certain defects in the subsurface, which degrades the device's properties. The project aims to explore atomic layer etching (ALE) for diamond, as this process very gently removes layers atom by atom. This process has been demonstrated for certain semiconductors, such as GaN, as reported by the Grenoble-Tsukuba research unit in 2018, and J-FAST was the first to demonstrate the process's effectiveness for diamond. However, there is a need to better understand the mechanisms at work at the atomic scale and to optimize the process for targeted applications (efficient photon extraction and increased mobility in diamond transistors).

Expected skills:
- a strong background in condensed matter physics and chemistry
- ability to conduct experimental work, particularly in cleanrooms, etching laboratories, and optical spectroscopy laboratories
- excellent communication skills
- teamwork
- international mobility

Your Work Environment

The PhD candidate will be part of the dual-degree PhD program between the University of Tsukuba, Japan, and the University of Grenoble Alpes, France. The work will be conducted partly in Tsukuba (J-FAST) and partly in Grenoble (NEEL, LTM), and may include:
• Understanding the mechanisms of the ALE process using an ICP-RIE etcher. The process will be analyzed using available in-situ diagnostic tools and controlled by plasma parameters.
• Performing ALE etching on diamond samples intended for specific applications:
- Single crystals prepared at NIMS (Dr. Teraji) or at NEEL with colored centers, for the fabrication of photonic structures
- Thin diamond films, lightly doped with boron (p-type), or p++/p- diamond multilayers supplied by DiamFab (a NEEL startup), processed to fabricate MOS capacitors and transistors.
• Study surface properties after etching using optical spectroscopy, positron annihilation spectroscopy (PAS), capacitance measurements, admittance spectroscopy, and DLTS.

Institut NÉEL is a CNRS unit (UPR 2940) under agreement with the University Grenoble Alpes. The laboratory is related to the CNRS Physique. It is located in Grenoble, in the heart of a unique scientific, industrial and cultural environment. It is one of the largest French national research institutes for fundamental research in condensed matter physics enriched by interdisciplinary activities at the interfaces with chemistry, engineering and biology. It consists of 450 employees, including 175 researchers.
CNRS is a public, scientific and technological organization.
The core mandate is to identify, to carry out or to have carried out, either alone or with partners, all research that advances science or contributes to the country's economic, social, and cultural progress. Internationally recognized for the excellence of its scientific research, the CNRS is a reference in the world of research and development, as well as for the general public.

The hosting teams at Institut Néel are "WIDE BANDGAP SEMICONDUCTORS" – SC2G et "NANOPHYSICS AND SEMICONDUCTORS" – NPSC, which form part of the PLUM department.

Constraints and risks

Double-degree thesis program between UGA and the University of Tsukuba. The doctoral student will therefore spend between 12 and 18 months in Tsukuba.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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