Activity

	Acerde provides scientific studies and services in the field of High Temperature Chemical Vapor Deposition (HTCVD). The scientific team is specialized in the synthesis of refractory materials with high-crystal properties, using CVD technology  mainly from chlorides and fluorides. High temperatures are used to synthesize high quality materials and  also provide access to materials requiring high temperature of synthesis such as nitrides and carbides.             CVD reactors designed for  silicone carbide free standing wafers elaboration and large scale coating (also BN and AlN coating)  CVD reactor for W and W carbide deposition Reactors are designed and 'home built' by Acerde's engineers and technicians: 3 reactors are currently operational. They have been designed and optimized for the deposition of tungsten or  silicon based materials, and nitrides such as  W, WC, SiC, AlN and BN. A new reactor (currently in development) will be exclusively dedicated to the manufacture of single crystal substrates of  aluminum nitride (AlN) for the UV LEDs development. .        Acerde proposes to synthesize  many materials  by HTCVD (see table below) whose properties are recognized in terms of bio-compatibility, mechanical resistance, chemical inertia and thermal conductivity. In addition, high temperatures allow to develop new compounds or known materials which are unable to be elaborated by other traditional manufacturing processes.    Chemical Vapor Deposition  at high temperatures is particularly suitable for the following requirements: Advantages of High Temperature Chemical Vapor Deposition : Deposition and coating on 2D and 3D sustrates, simple or complex geometries Free standing samples Multilayers deposition Control of coating thickness (µm to mm) Control of size and orientation of grains Control of purity and doping      (a)       (b)  Examples of 2D and 3D coating made by HTCVD: (a) Free standing square wafer (500µm thick SiC) for optical application. (b) Large scale SiC coating (3mm thick inside a 150mm graphite cylinder)     Acerde also offers services in multi-scales characterization and analysis of materials (X-ray Diffraction, SEM, TEM, AFM, EBSD, ...), and develops original solutions adapted to your needs (realization of buffer layers, thermal treatments at high temperatures and cryogenic treatments , multi-layer deposition, ...)   (a)         (b)   SEM pictures of the cross section of a (a) SiC  oriented thick wafer (chemically attacked to reveal the grain size) and (b) the surface  of a thin epitaxial AlN film deposited on SiC substrate  by HTCVD.

  

Coatings	W	Re	Mo	Ir	Nb	Ta	WC W2C	Refractories alloys	Silicides (Mo, W)
Substrate
Graphite
Molybdenum
Tungsten
Nickel
Steel
Alumina
Monel
Rhenium
Tanlalum Niobium
Copper
Silicon
Titanium
Zirconium
UO2
Graphite fibers
Silica fibers
Nicalon fibers
Massive coatings

Coalings	SiC	Si3N4	B4C	BN	TiN	TiB2	W2B	Pyrolytic C PYC	TIC
Substrate
Graphite fibers
Nicalon fibers
Nextel fibers
SiIica fibers
Graphite
Tungsten
Nickel
Steel
Titanium
Massive coatings