Amorphous silicon carbide (a-SiC) is a wide-bandgap semiconductor with high robustness and biocompatibility, making it a promising material for applications in biomedical device passivation. a-SiC thin film deposition has been a subject of research for several decades with a variety of approaches investigated to achieve optimal properties for multiple applications, with an emphasis on properties relevant to biomedical devices in the past decade. This review summarizes the results of many optimization studies, identifying strategies that have been used to achieve desirable film properties and discussing the proposed physical interpretations. In addition, divergent results from studies are contrasted, with attempts to reconcile the results, while areas of uncertainty are highlighted.

The purpose of this paper is to give a review on the state of the art of polycrystalline SiC material grown by low-pressure chemical vapor deposition (LPCVD). Nowadays, LPCVD is the main technique used for the deposition of polycrystalline SiC, both in academic research and industry. Indeed, the LPCVD technique is today the most mature technique to grow high purity polycrystalline thin films with controlled thickness and structure over a large area (>50 cm) and/or 3D substrate. Its ability to have a high degree of modification on the growth conditions and the chosen precursor system allows the deposition of polycrystalline SiC films in various substrates with tailored properties according to the desired application. After a short introduction on the SiC material and its growth by the LPCVD technique, a review of theoretical studies (thermodynamics and kinetics) related to the CVD SiC growth process is given. A synthesis of the experimental studies is made focusing on the effect of the growth conditions on the properties of the deposited SiC polycrystalline material. Despite the numerous results, a full understanding of them is limited due to the complexity of the LPCVD process and the polycrystalline SiC structure. The conclusions show that the growth conditions, like temperature, chamber pressure, (C/Si)_(g), (Cl/Si)_(g), and doping have an impact on the microstructure and on the corresponding properties of the polycrystalline SiC films. Future perspectives are given in order to improve our understanding on the polycrystalline–SiC–LPCVD process and to enable the growth of tailor-made polycrystalline SiC films for future applications.

Polycrystalline nitrogen-doped cubic silicon carbide (3C-SiC) thin films are grown on 2″ Si wafers by a low-pressure chemical vapor deposition (LPCVD) technique with the aim for them to be used as support and active materials in microelectronic devices for neural interfaces. The effect of deposition temperature on the structural, mechanical, and electrical properties is investigated. The growth rate is varying, from 1 μm/h to 14 μm/h, along with the deposition temperature. We show that the structural and electrical properties of polycrystalline SiC are modified when changing the deposition temperature. Films with resistivity as low as (10.0 ± 0.5) mΩ·cm, a low residual stress of (−397 ± 158) MPa, and a low root mean square surface roughness of (53 ± 19) nm are achieved. Accelerated aging tests in heated phosphate buffer solution (PBS) show an etching rate of less than 1 nm/day and a steady low electrical resistivity for 77 days, indicating that the nitrogen-doped polycrystalline SiC is a chemically stable material, capable of chronic stability in a saline electrolyte.

For the first time, we have implemented new kinds of ISFETs based on silicon carbide (SiC). Thanks to its chemical inertness, SiC is an interesting semiconductor for the development of chemically robust and biocompatible ISFETs. The challenge is to replace Si NWFETs for biochemical sensing due to the lack of long-term stability of Si NWs in aqueous solutions. More particularly, we fabricated a micro/nanowire SiC-based ion-sensitive junction field-effect transistor (SiC-ISJFET) and studied its sensitivity to pH variations. The obtained sensitivity reaches 500 mV/pH, making it the first SiC pH sensor with performance equaling that of the latest NWFET Si-based pH sensors.

Polycrystalline nitrogen doped cubic silicon carbide (3C-SiC) thin films, are grown on 2” Si wafers by low-pressure chemical vapor deposition (LPCVD) technique with the aim to be used as support and active material in microelectronic devices for neural interfaces. The effect of deposition temperature on the structural, mechanical and electrical properties is investigated. Growth rate is varying from 1 μm/h to 14 μm/h, along with the deposition temperature. We show that the structural and electrical properties of polycrystalline SiC are modified when changing the deposition temperature. Films with resistivity as low as (10.0 ± 0.5) mΩ·cm, low residual stress of (-397 ± 158) MPa and low root mean square surface roughness of (53 ± 19) nm are achieved. Accelerated aging tests in heated phosphate buffer solution (PBS) show an etching rate less than 1 nm/day and a steady low electrical resistivity for 77 days indicating that the nitrogen-doped polycrystalline SiC is a chemically stable material, capable of chronic stability in a saline electrolyte.