Organometallic Vapor Phase Epitaxy OMVPE

As mentioned above, CVD, the most general term describing the deposition process, implies nothing about the crystallinity of the grown layer. Epitaxy is directed at single crystal layers on single crystal substrates. Vapor phase epitaxy (VPE) was coined to parallel liquid phase epitaxy (LPE). 

The term organometallic describes precursors which contain a direct metal-carbon interaction, be it a or Ji in nature. This is in parallel with traditional chemical nomenclature. Metalorganic, in contrast, now is accepted widely as the description for any metalorganic containing ligand precursor for CVD. This includes, for example, metal alkoxides and metal amides. The metal carbonyl work of Mond, last century, is one early example of OMCVD. 

The potential of CVD has begun to bear fruit in many areas. The process ability to rapidly coat non-planar objects in a cost-effective manner has contributed to a rapid rise in the adaptation of the technique. For example, solar cells and layers now are routinely fabricated by CVD approaches. Additionally, synthetic gold coatings (off-stoichiometry TIN) are put down for cosmetic reasons on large volumes of personal jewelry. The scratch-resistant material makes for a tough outer shell at an exceptionally attractive economic cost. 

Despite these successes, several problems remain, including the need for expensive reactants and the large number of parameters that must be controlled precisely to obtain the necessary uniformity and reproducibility for microelectronic and optoelectronic applications. Additional challenges to overcome include the use of hazardous materials and the generation of a substantial volume vapor phase waste stream. 

One method which has been investigated extensively and applied widely over the last decade is plasma-enhanced CVD (PECVD). Many CVD processes employing plasmas still require substrate heating, since plasma temperatures typically are several hundred degrees lower than those demanded for conventional CVD. Thus, the technique often is known as plasma-enhanced CVD (PECVD) or plasma-assisted CVD (PACVD). 

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The potential benefits of CVD over other film deposition techniques are that CVD-derived films can be deposited under conditions that give conformal coverage, they can be deposited at low temperatures, there can be a high level of compositional control, thin layers can be deposited, the technique can be scaled to coat large areas uniformly, and there is also the possibility for area-selective deposition13 as a result of the chemical nature of this process. The details of CVD and related chemical deposition processes such as atomic layer epitaxy (ALE), organometallic vapor-phase epitaxy (OMVPE), and others have been described elsewhere.6... 

We found recently(8) that organic ditellurides (RTeTeR, R=some organic moiety) are potentially useful tellurium source compounds for the preparation of Te-containing II-VI compounds by organometallic vapor phase epitaxy (OMVPE). In the course of those investigations we found (9) that di(aryltellurato) mercury compounds [(RTe)2Hg], formed from the ditelluride and Hg,... 

A method that overcomes some of these limitations is metal-organic chemical vapor deposition (MOCVD), sometimes called organometallic vapor phase epitaxy (OMVPE) °. An organometallic compound such as a group IIB alkyl reacts with a chalcogenide hydride on a substrate that is at the highest temperature in the chamber ... 

Organometallic Vapor Phase Epitaxy (OMVPE) System Technology. . . 208... 

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