Silicon deposition

Molecular beam epitaxy is a non-CVD epitaxial process that deposits silicon through evaporation. MBE is becoming more common as commercial equipment becomes available. In essence, silicon is heated to moderate temperature by an electron beam in a high vacuum... 

Several precursors and CVD reactions are available to deposit silicon. The deposit can be either single crystal (epitaxial), polycrystalline, or amorphous. 

Reactions (1), (2) and (3), which all use ammonia, have a tendency to deposit silicon nitride with a high ratio of included hydrogen, especially at the lower temperatures and if a plasma is used. This tendency is often detrimental but it can be remedied, at least to some degree, by using nitrogen instead of ammonia ... 

Many reactions are being used to deposit silicon dioxide, both experimentally and in production, and many more are being investigated in the laboratory. The selection depends on the application, the temperature limitations, the type of equipment available, and other factors. 

In the case of H in low-temperature deposited silicon nitride films, ion beam techniques have again been used to calibrate IR absorption. The IR absorption cross sections most often quoted in the literature for Si—H and N—H bonds in plasma-deposited material are those of Lanford and Rand (1978) who used 15N nuclear reaction to calibrate their IR spectrometry. Later measurements in CVD nitride films, using similar techniques, confirmed these cross sections (Peercy et al., 1979). 

The steam reformer is a serpentine channel with a channel width of 1000 fim and depth of 230 fim (Figure 15). Four reformers were fabricated per single 100 mm silicon wafer polished on both sides. In the procedure employed to fabricate the reactors, plasma enhanced chemical vapor deposition (PECVD) was used to deposit silicon nitride, an etch stop for a silicon wet etch later in the process, on both sides of the wafer. Next, the desired pattern was transferred to the back of the wafer using photolithography, and the silicon nitride was plasma etched. Potassium hydroxide was then used to etch the exposed silicon to the desired depth. Copper, approximately 33 nm thick, which was used as the reforming catalyst, was then deposited by sputter deposition. The reactor inlet was made by etching a 1 mm hole into the end... 

Activation by Displacement Deposition. Silicon can be made catalytic for electroless deposition of Ni by replacing the surface Si atoms with Ni atoms (58,62) ... 

List of mordenltes and saturated surface concentration of deposited silicon... 

The relationship between the surface concentration of deposited silicon and the conversion ratio Is shown In Fig. 4. On the HM-10 and NaM-10, the cracking of 2,2,4-trlmethylpentane was Inhibited completely at the deposition of 14 nm" of silicon surface concentration. On the other hand, on HM-15, HM-20, KaM-15,... 

The substrate for this CVD process is a thin silicon rod, called a slim rod, which serves as a nucleation site for the depositing silicon. After deposition, the EGS, or polysilicon, is processed in the Czochralski (CZ) growth process. 

Plasmas can be used in CVD reactors to activate and partially decompose the precursor species and perhaps form new chemical species. This allows deposition at a temperature lower than thermal CVD. The process is called plasma-enhanced CVD (PECVD) (12). The plasmas are generated by direct-current, radio-frequency (r-f), or electron-cyclotron-resonance (ECR) techniques. Figure 15 shows a parallel-plate CVD reactor that uses r-f power to generate the plasma. This type of PECVD reactor is in common use in the semiconductor industry to deposit silicon nitride, and glass (PSG)... 

Again, double liquid treatments of HMDS did not prove adequate for polysilicon gate substrates, substrates comprised of amorphous deposited silicon as... 

Plasma-deposited silicon nitride contains large amounts of hydrogen, typically in the range of 20—25 atomic % H, and has polymer-like properties. The electrical resistivity of the film depends on the deposition temperature, the film stoichiometry, and the amounts of hydrogen and oxygen in the film. 

Cl2) or hydrogen chloride (HC1). The silane gas has to be diluted with an inert gas to prevent precipitation in the gas phase. In addition, small amounts of phosphane PH3 or diborane B2H6 can be added to dope the deposited silicon layer. 

Narushima, T., Goto, T., Iguchi, Y., Hirai, T., (1991), High-temperature active oxidation of chemically vapor-deposited silicon carbide in an Ar-02 atmosphere , J. Am. Ceram. Soc., 74, 2583-2586. 

For silicon nitride films made in a cold-wall, pa rail el-pi ate reactor operating at 50 kHz, 200 mTorr, gas flows of SiH4/NH3/N2 = 140/270/800 seem and 500 watts of power, we can compare chemical and physical properties with thermally-deposited silicon nitride. Such a comparison is shown in Table 1.2... 

Passivation is needed to insulate the backplane from the OLED stacks everywhere except the ITO and bonding contact areas. Unlike poly-Si and a-Si H backplanes, on which both organic and inorganic passivation layers can easily work, the device passivation technique needs extra consideration for pentacene TFTs. We explored several different materials for passivation of pentacene TFTs, including poly(vinyl alcohol) (PVA), room temperature plasma-enhanced chemical vapor deposition silicon nitride (RT PECVD SiN), and vapor-deposited parylene. 

Holzapfel M, Buqa H, Krumeich F, Novak P, Petrat FM, Veit C. Chemical vapor deposited silicon/ graphite compound materials as negative electrode for lithium-ion batteries. Electrochem Solid-State Lett 2005 8 A516-A520. 

Satin A CVD process for depositing silicon nitride films on semiconductor devices at the relatively low temperature of 500°C. The identity of the gaseous reactant is proprietary. Developed by Aviza Technology and Air Liquide in 2004. 

Gorecki C (2000) Optimization of plasma-deposited silicon oxinitride films for optical channel waveguides. Opt Lasers Eng 33 15-20... 

Recent converter hardware development has concentrated on flame heated devices for terrestrial topping cycle applications. Significant progress has been made with chemical vapor deposited silicon carbide as the oxidation protection hot shell. Flame heated converters have now been operated by Thermo Electron Corporation with emitter temperatures over 1700 K for 7000+ hours ( ). 

In, the central zone, the regular distribution of transverse cracks shows that the induced strain is rather homogeneous. Consequently, many analytical models can be applied in order to determine the intrinsic parameters of the coatings. The critical cracking energy and the mode I fracture toughness of the deposited silicon carbide film were assessed by means of the model presented previously. It should be remembered that it was first established and developed for composite materials based on research by Kelly and subsequently by Hu ", that when the stress normal to the coating reaches a critical value... 

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