L-CVD

SNR L/CVD Carbon Resist System. We have proposed another approach to improve the nanometer-scale resolution of the SNR 2-layer resist system, viz., the application of carbon films as the bottom layer material. (5) Carbon films prepard by plasma CVD are hard and thermally stable. Figure 5 shows about 40 nm-wide SNR/carbon patterns with a 150 nm pitch on a Si substrate. The narrow lines are well resolved with a steep profile, and the lines at both edges of the pattern have not bent or fallen down. This excellent stability of nanometer-scale carbon patterns facilitates the evaluation of the resolution limit SNR in 2-layer resist application. 

Figure D.l. CVD phase diagram of MTS-BC13-H2 system (40Pa, 1127°C, a = H2/MTS, P = MTS/BCI3) [18]...

PE-CVD applies a plasma for activation and is also a low-temperature process. L-CVD uses laser activation. 

Conner, L., CVD Diamond—Beyond the Laboratory, in Proc. Conf. on High-Performance Thin Films, GAMI, Gorham, ME (1988)... 

Copper is an attractive metallisation element because of its high conductivity. It has been added to Al in low concentrations (AlSi(l%)—Cu(0.5%)) to improve conductive priorities. Selective, low temperature copper CVD processing, using copper(I) P-diketonate compounds, has been carried out (23). 

Fluoroall l-SubstitutedTitanates. Tetraliexafluoroisopropyl titanate [21416-30-8] can be prepared by the reaction of TiCl and hexafluoroisopropyl alcohol [920-66-17, in a process similar to that used for TYZOR TPT (7). Alternatively, it can be prepared by the reaction of sodium hexafluoroisopropoxide and TiCl ia excess hexafluoroisopropyl alcohol (8). The fluoroalkyl material is much more volatile than its hydrocarbon counterpart, TYZOR TPT, and is used to deposit titanium on surfaces by chemical vapor-phase deposition (CVD). 

L.I. Medved s Institute of Ecohygiene and Toxicology Ukraine, 03680, Kyiv, 6 Heroiv Oborony Str. e-mail cvd medved.kiev.ua... 

The structure of a CVD material can be classified into three major types which are shown schematically in Fig. 2.13. In Zone (A), the structure consists of columnar grains which are capped by a domelike top. In Zone (B), the structure is also columnar but more faceted and angular. In Zone (C), it consists of fine accost grains. Examples of these structures are shown in Fig. 2.14. " This is the CVD equivalent of the structural model for vacuum-evaporated films first introduced by Movchan and Demshishin.P l... 

Zilko, J. L., Metallo-Organic CVD Technology and Equipment, in Handbook of Thin-Film Deposition Processes and Techniques, (K. K. Shuegraf, ed.), Noyes Publications, Park Ridge, NJ (1988)... 

CVI is a special CVD process in which the gaseous reactants penetrate (or infiltrate) a porous structure which acts as a substrate and which can be an inorganic open foam or a fibrous mat or weave. The deposition occurs on the fiber (or the foam) and the structure isgradually densified to form a composite.The chemistry and thermodynamics of CVT are essentially the same as CVD but the kinetics is different, since the reactants have to diffuse inward through the porous structure and the by-products have to diffuse out.f l Thus, maximum penetration and degree of densification are attained in the kinetically limited low-temperature regime. 

Sullivan, L. A., and Bin Han., Vapor Delivery Methods for CVD, An Equipment Selection GmdQ, Solid State Technology, pp. 91-101 (May 1996)... 

In addition to the thermal CVD reactions listed above, tungsten can be deposited by plasma CVD using Reaction(l)at350°C.[ ll P At this temperature, a metastable alpha structure (aW) is formed instead of the stable be.c. Tungsten is also deposited by an excimer laser by Reaction (1) at < 1 Torr to produce stripes on silicon substrate.P l... 

Graphite is commonly produced by CVD and is often referred to as pyrolytic graphite. It is an aggregate of graphite crystallites, which have dimensions (L ) that may reach several hundred nm. It has a turbostratic structure, usually with many warped basal planes, lattice defects, and crystallite imperfections. Within the aggregate, the crystallites have various degrees of orientation. When they are essentially parallel to each other, the nature and the properties of the deposit closely match that of the ideal graphite crystal. 

Schafer, L., Saltier, M., and Klages, C. P., Upscaling of the Hot-Filament CVD Process for Deposition of Diamond Films on Large-Area Substrates, m Applications of Diamond Films and Related Materials, (Y. Tzeng, et al., eds.), Elsevier Science Publishers, pp. 453-460(1991)... 

In addition to the thermal CVD reactions mentioned above, plasma CVD is used for the low temperature deposition of boron.i l... 

Amorphous Silicon. Amorphous silicon is generally deposited by Reaction (4) at a deposition temperature of 560°C and at low pressure (ca. 1 Torr).P l Helium RF plasma CVD is also commonly used, especially in the production of solar photovoltaic devices. 

Groner, P., Gimzewski, J., and Veprek, S., Boron and Doped Boron First Wall Coatings by Plasma CVD, / Nucl. Mater., 103(l-3) 257-260(1981)... 

The following CVD reactions are commonly used to deposit boron carbide.PH l All three reactions use excess hydrogen. The most common is Reaction (1). 

HfC is produced by CVD mostly on an experimental basis. The most common deposition system is the reaction of the metal chloride with a hydrocarbon, which can be propane (C3H8), propene (C3H6), toluene (C7Hg), or methane (CH4) as follows b H l... 

The useful temperature range is lower than that of Reaction (1) with 800°C being typical. A pressure of approximately 10 Torr is typical, although atmospheric pressure can also be used.P l Plasma CVD has been used with Reactions (2) and (3) to deposit SiC at considerably lower temperatures (200-500°C).P l... 

Ferro, G., et at, Infrared Kinetic Study of Ultrathin CiC Buffer Layers Grown by Reactive CVD, Thin Solid Films, 278(l-2) 22-27(1996)... 

The major application of CVD aluminum nitride is for electronic components. At this time, most of the AIN powder is produced by CVD and originates in Japan and is used by the Japanese industry.b l... 

Like synthetic diamond, C-BN is normally obtained by high-pressure processing. Efforts to synthesize it by CVD at low pressure are promising. It is deposited in an electron-cyclotron-resonance (ECR) plasma from a mixture of BF3 and either ammonia or nitrogen at 675°C on an experimental basis.F l Like CVD diamond, it is also deposited by the hot-filament method using diborane and ammonia diluted with hydrogen at 800°C.P 1... 

Another example of the CVD of TiN is deposition by laser activation using a CO2 laser with N2H2 and TiC reactant gases. Deposition temperatures are not mentioned but presumed to be low. The composition of the film is substoichiometric (N/Ti[Pg.285]

Fluorinated Silicon Oxide. The introduction of fluorine in the ratio of 2 to 14 at.% lowers the dielectric constant, which is reported as low as 3.0. This is a major factor in the design of dielctric films. The CVD of these fluorinated compounds is accomplished by plasma-CVD and usually with Sip4 as a fluorine source. Also available are fluorinated compounds, such as fluorotriethoxysilane (FTES), l,2bis(methyldifluorosilyl)ethane, and 2,5disilahexane.P2]... 

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