Vapor deposition chamber

Figure 3.20 Three gases being introduced into a chemical vapor deposition chamber.

Zazzera L, Reagen W, Cheng A. Infrared study of process emissions during CjFj/Oj plasma cleaning of plasma enhanced chemical vapor deposition chambers. J Electrochem Soc. 1997 144 3597-601. 

Applications of such tri-blends include semiconductor devices, including microchips, flat panel displays, and the hke. In the manufacture of such apparatus, such blends can be used as components of the vapor deposition chamber, process housing components, and materials holding fixtures or molds, in order to be inert to the vapor deposition environment and to prevent off-gas contamination. These blends may also be used in components of semiconductor etching, ashing, wafer transportation, and as hard-disc media cassettes where support components may function as a seal, insulator, holding or transportation device which must endure exposure to the harsh processing environments. Further applications for such blends can be found in various industrial, chemical, and petrochemical processes where the temperature resistance in chemical environments extends the life cycle of parts used in such fabrication processes. 

Vacuum Deposition. Vacuum deposition, sometimes called vacuum evaporation, is a PVD process in which the material is thermally vaporized from a source and reaches the substrate without coUision with gas molecules in the space between the source and substrate (1 3). The trajectory of the vaporized material is therefore line-of-sight. Typically, vacuum deposition takes place in the pressure range of 10 10 Pa (10 10 torr), depending on the level of contamination that can be tolerated in the resulting deposited film. Figure 3 depicts a simple vacuum deposition chamber using a resistively heated filament vaporization source. 

In PECVD, the plasma generation region may be in the deposition chamber or precede the deposition chamber in the gas flow system. The latter configuration is called remote plasma-enhanced CVD (RPECVD). In either case, the purpose of the plasma is to give activation and partial reaction/reduction of the chemical precursor vapors so that the substrate temperature can be lowered and still obtain deposit of the same quaUty. 

Carbon Composites. In this class of materials, carbon or graphite fibers are embedded in a carbon or graphite matrix. The matrix can be formed by two methods chemical vapor deposition (CVD) and coking. In the case of chemical vapor deposition (see Film deposition techniques) a hydrocarbon gas is introduced into a reaction chamber in which carbon formed from the decomposition of the gas condenses on the surface of carbon fibers. An alternative method is to mold a carbon fiber—resin mixture into shape and coke the resin precursor at high temperatures and then foUow with CVD. In both methods the process has to be repeated until a desired density is obtained. 

Another delivery system is shown in Fig. 5.4, where a mass-flow controller injects a carrier gas into a heated bubbler. The carrier gas becomes saturated with the reactant vapor, which is then carried into the deposition chamber through a pressure controller and flowmeter.C]... 

MOCVD Reactions. A great deal of interest has been generated by the availability of two metallo-organic titanium compounds, tetrakis-diethylamino titanium (TDEAT) andtetrakis-dimethylamino titanium (TDMAT). These precursors make possible the deposition of TiN at lower temperature.[ " k l These compounds are liquid at room temperature. A flow of helium bubbling through the warm precursor entrains the vapor into the deposition chamber. Deposition temperature is approximately 320°C. The following reactions occur ... 

Electrocatalytic activity of supported metal particles has been investigated on surfaces prepared in an ultrahigh vacuum (UHV) molecular beam epitaxy system (DCA Instruments) modified to allow high throughput (parallel) synthesis of thin-film materials [Guerin and Hayden, 2006]. The system is shown in Fig. 16.1, and consisted of two physical vapor deposition (PVD) chambers, a sputtering chamber, and a surface characterization chamber (CC), all interconnected by a transfer chamber (TC). The entire system was maintained at UHV, with a base pressure of 10 °mbar. Sample access was achieved through a load lock, and samples could be transferred... 

Fig. 2 (a) Edwards E308 evaporator. One quartz-crystal thickness monitor is pointed towards the Au source to monitor Au vapor deposition on chamber walls the other monitors Au deposited through the shadow mask atop the organic layer. In the cold Au deposition, a small amount of Ar gas is added to the chamber to cool the Au atoms to room temperature before they physisorb atop the cryocooled organic monolayer, (b) Geometry of an Au I monolayer I Au pad sandwich, with electrical connections made using a Ga/In eutectic... 

The Re0 7HZ catalyst was prepared by the following procedure. Methyl trioxorhenium (MTO) was sublimed under vacuum at 333 K and the vapor was allowed to enter the chamber, where the zeolites were pretreated in situ at 673 K under vacuum. After the chemical vapor deposition (CVD) into zeolite pores, undeposited MTO was removed by evacuation at RT. The catalyst was treated at 673 K in He before using. 

Figure 15 records an example of this relationship between incoming thickness variation and post-CMP thickness variation. The incoming thickness variation is due to the fact that the TEOS film was deposited in two different plasma-enhanced chemical vapor deposition (PECVD) chambers, which are not calibrated identically [13]. As can be seen in Fig. 15, the pre-CMP wafer-to-wafer thickness variation pattern has been perfectly preserved after CMP. 

---