Epitaxial Growth Equipments

The modern microelectronics and semiconductor industries have imposed severe demands on the quality of films produced by the silicon epitaxy process and the epitaxial film deposition techniques need to fulfill several general 

A basic epitaxial reactor should consist of at least the following items (a) a reactor tube or chamber to isolate the epitaxial growth environment (b) a system that distributes the various chemical species for epitaxial growth in a very controlled manner (c) a system for heating the wafers and (d) a system for scrubbing the effluent gases. 

For photovoltaic applications, several reports illustrate the growing interest in research to develop techniques of epitaxy on large surfaces. The major challenge is to get a device at a lower cost. 

at the University of Madrid, Rodriguez et al. [22] have designed a reactor for the recycling of gases that are not consumed. This innovation appears of paramount importance, because the gas consumption efficiency 

Another example is the work of Kunz et al. [23] at ZAE Bayern, on the design of an epitaxial reactor that uses the internal convection of gases to obtain homogeneous layers on large surfaces of more than (40 x 40) cm2 (Fig. 10.9). This system, called CoCVD (Convection-assisted CVD), uses 

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Metallo-organic CVD (MOCVD) is a specialized area of CVD, which is a relatively newcomer, as its first reported use was in the 1960s for the deposition of indium phosphide and indium anti-monide. These early experiments demonstrated that deposition of critical semiconductor materials could be obtained at lower temperature than conventional thermal CVD and that epitaxial growth could be successfully achieved. The quality and complexity of the equipment and the diversity and purity of the precursor chemicals have steadily improved since then and MOCVD is now used on a large scale, particularly in semiconductor and opto-electronic applications.91P1... 

Growth Procedures. The exact procedures for the growth of devicequality epitaxial films by LPE vary with the deposited material, the design of the growth equipment, and the structure to be fabricated. The general procedure involves preparation of the substrate, loading of the melt constituents and pretreatment of the system, and growth. 

The structures were grown in an ultra high vacuum (UHV) chamber VARIAN with a base pressure of 2-10 °Torr equipped with differential reflectance spectroscopy (DRS) [3] for a study of optical properties of the samples. Samples were cut from n-type 0.3 D cm Si(l 11) substrates. The silicon was cleaned by flashes at 1250 °C (7 times). Surface purity was controlled by AES. RDE was carried out at 500 °C, 550 °C, and 600 °C. The Cr deposition rate was about 0.04 nm/min controlled by a quartz sensor. An additional annealing during 2 min at 700 °C was done for all samples before the growth of silicon epitaxial cap layer. 

Growth experiments were carried out in two ultra high vacuum (UHV) cambers with sublimation sources of Si, Fe and Cr and quartz sensors of film thickness. Optical properties of the samples were studied in UHV chamber VARIAN (210 10Torr) equipped with differential reflectance spectroscopy (DRS) facilities. The samples surface was studied in the second UHV chamber (1 -10 9 Torr) equipped with LEED optics. Si(100) and Si(l 11) wafers were used as substrates for different series of the growth experiments. For the growth of silicide islands, metal films of 0.01-1.0 nm were deposited onto silicon surface. Silicon overgrowth with the deposition rate of 3-4 nm/min was carried out by molecular beam epitaxy (MBE) at 600-800 °C for different substrates. The samples were then analyzed in situ by LEED and ex situ by HRTEM and by... 

Using a commercial MW-PCVD reactor equipped with a substrate bias, nucleation and growth of epitaxially orientated diamond films can be achieved on silicon substrates by applying a three-step procedure consisting typically of ... 

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