Chemical vapor deposition doping control

Silicon, diamond, and metal deposition are all examples of elemental deposition. Compounds, particularly oxides, are also deposited by chemical vapor deposition. Some of the important oxides deposited as thin films include SiC>2, BaTiC>3, LiNbC>3, YBa2Cu30,. indium-doped SnC>2, and LiCoC>2. These materials have properties such as superconductivity or lithium ionic conductivity that make their production as thin films a much-studied area of research. If the oxide is to be deposited on the bare metal (e.g., depositing SiC>2 onto Si), chemical vapor deposition is not really needed. Controlling the oxygen partial pressure and temperature of the substrate will produce the oxide film Whether the film sticks to the substrate is another question The production of SiC>2 films on Si is an advanced technology that the integrated-circuit industry has relied on for many years. Oxide films on metals have been used to produce beautiful colored coatings as a result of interference effects (Eerden et al., 2005). 

Sacrificial oxide. The sacrificial oxide layer is deposited by low-pressure chemical vapor deposition (LPCVD) or plasma-enhanced chemical vapor deposition (PECVD). The layer is made of either undoped glass or phosphorous-silicon glass (PSG)-doped resulting in a final thickness of 1.5-2.5 pm. Low defect density, good etch rate control, uniformity and stress control have been accomplished for updoped oxide with a Novellus Concept One tool. 

Chemical vapor deposition (CVD) was applied to produce homogeneous thin films of pure and doped spinel cobalt oxide with similar morphology on the surface of planar and monolithic supports. The planar substrates were used to investigate the thermal stability and the redox properties of the spinel using temperature-programmed methods monitored by emission-FTIR spectroscopy, while the monolithic substrates were used to test the catalytic performance of the deposited films toward the deep oxidation of methane and to evaluate its durability. The high performance of cobalt oxide to oxidize methane in diluted streams was demonstrated at 500 °C. Furthermore, controlled doping of cobalt oxide layers with suitable cations was demonstrated for nickel as an example, which resulted in substantial increase of electric conductivity. 

Boron incorporated during a chemical vapor deposition (CVD) process is now proving to be the most popular means of imparting electrical conductivity on the diamond lattice for use in electrochemistry, both from a research perspective and commercially, for reasons that will be discussed later. There have been many reviews since 1983, both in journals [2-9] and books [10] on the use of diamonds in electrochemistry. This chapter aims to review the field and provide a comprehensive discussion on the current understanding of the fundamental factors controlling the response of boron-doped diamond (BDD) electrodes. Latest developments (as of 2014) are also highlighted. 

S. G. Im, K. K. Gleason, and E. A. Olivetti. 2007. Doping level and work function control in oxidative chemical vapor deposited poly(3,4-ethylenedioxythio-phene). Appl Phys Lett 90 152112-1-152112-3. 

The development of low-pressure synthesis methods for diamond, such as the chemical vapor deposition (CVD) technique, has generated enormous and increasing interest and has extended the scope of diamond applications. Highly efficient methods have been developed for the economical growth of polycrystalline diamond films on non diamond substrates. Moreover, these methods allow the controlled incorporation of an impurity such as boron into diamond, which in this case forms a ptype semiconductor. By doping the diamond with a high concentration of boron (B/C = O.Ol), conductivity can be increased, and semi-metallic behavior can be obtained, resulting in a new type of electrode material with all of the unique properties of diamond, such as hardness, optical transparency, thermal conductivity and chemical inertness [1,2]. 

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