Pressure Chemical Vapor Deposition Method Research Articles

Titanium dioxide thin films prepared by chemical vapor deposition

Abstract Titanium dioxide thin films were prepared by a low-temperature atmospheric-pressure chemical vapor deposition method in air. The source gases were generated by heating isopropyl alcohol solutions of titanium tetraacetylacetonate and bis(acetylacetonate) titanium diisopropoxide. On glass and silicon (100) substrates, an amorphous film can be obtained at a substrate temperature in the range 200–500°C, and a polycrystalline anatase film can be obtained at a substrate temperature above 500°C.

Fluorine-doped indium oxide thin films prepared by chemical vapor deposition

Transparent conductive fluorine-doped indium oxide thin films were prepared by an atmospheric-pressure chemical vapor deposition method. The raw material was [C7H15COO]2 In[H(CF2)4COO]. The polycrystalline films were obtained at a reaction temperature in the range of 350–450 °C. This chemical vapor deposition method incorporates fluorine atoms into a crystalline structure and consequently leads to a high carrier concentration, yielding fluorine-doped indium oxide films of low resistivity. For the 320-nm-thick film deposited at 380 °C, the resistivity was 4.4×10−4 Ω cm, and the sheet resistance was 13.8 Ω/⧠.

Analysis of hydrogen in low pressure diamond layers

The hydrogen concentration of diamond layers produced by a low pressure chemical vapour deposition method on SiAlON substrates has been determined by means of the 15N nuclear reaction analysis technique. The results show distinct differences in the hydrogen content which depend on the gas pressure and on the acetone-hydrogen gas mixture used in the deposition. The resulting diamond morphology is found to be related to the hydrogen content, well-faceted layers containing about 0.2–0.9 at % H, and balas-type layers with about 1.4 at.%H. Contrary to expection, no relation between the crystal size in the well-faceted layers and the average hydrogen content was found. Additional Rutherford backscattering measurements revealed a high purity of the films with respect to elements heavier than carbon.

Cobalt oxide thin films prepared by chemical vapor deposition from cobalt (II) acetate

Cobalt oxide thin films were prepared by a low-temperature atmospheric-pressure chemical vapor deposition method. The raw material was cobalt (II) acetate which is non-toxic and easy to handle. Polycrystalline films were obtained at a reaction temperature above 300°C. From near-normal reflection measurements it follows that the films have solar absorptance α = 0.73 and thermal emittance ϵ = 0.089.

The oxide nitride oxide film deposition on the tunnel-structured polycrystalline silicon (polysilicon) electrodes for high-density dRAMs

The uniform deposition of the oxide nitride oxide (ONO) film on the tunnel-structured polysilicon electrodes was examined by measuring the electrical characteristics of the capacitor and by using transmission electron microscopy. The conventional low pressure chemical vapor deposition method was adopted for the deposition of the nitride film of the ONO. The tunnel length is varied from 1.6 to 15.6 μm. The ONO film deposited over the entire tunnel of 15.6 μm showed good electrical characteristics, and the thickness uniformity as well. In addition to the maximum tunnel length which can accommodate the uniform ONO deposition, the growth mechanism of the ONO film inside of the tunnel is discussed.

Cobalt thin films prepared by chemical vapor deposition from cobaltous acetate

Cobalt thin films were prepared by a low-temperature atmospheric-pressure chemical vapor deposition method. The raw material was cobaltous acetate which is nontoxic and easy to handle. At a reaction temperature of 300 °C, [111]-oriented polycrystalline films can be obtained on amorphous substrates. Increasing the H2 partial pressure over the requirement for both the highest deposition rate and lowest resistivity promotes the crystallization with [111] preferential orientation of the film without affecting the crystallite size. Cobaltous acetate appears to offer a viable alternative to cobalt acetylacetonate for low-temperature cobalt film production.

Indium tin oxide thin films prepared by chemical vapour deposition

Transparent conductive indium tin oxide thin films were prepared by an atmospheric pressure chemical vapour deposition method without using an oxygen donor. The raw materials were indium 2-ethylhexanoate and tin(IV) chloride, which are inexpensive and easy to handle. Polycrystalline films were obtained at a reaction temperature of 400°C. The tin content in the film is adjustable by changing the ratio of the flow rate of the carrier gas. For a 430 nm thick film deposited at 400°C, the resistivity was 2.9×10 −4 Ω cm , and the transmittance was more than 80% in the wavenumber range above 550 nm. The effects of tin doping on the structure and characteristics of the film are discussed by comparing the results with the corresponding values for non-doped indium oxide film.

Aluminum oxide thin films prepared by chemical vapor deposition from aluminum acetylacetonate

Amorphous aluminum oxide thin films were prepared on glass and silicon (100) substrates by a low-temperature atmospheric-pressure chemical vapor deposition method. The raw material was aluminum acetylacetonate, which is nontoxic and easy to handle. The substrate temperature could be lowered to 250 °C by the thermal decomposition of aluminum acetylacetonate in air.

Aluminum oxide thin films prepared by chemical vapor deposition from aluminum 2-ethylhexanoate

Aluminum oxide thin films were prepared by a low-temperature atmospheric-pressure chemical vapor deposition method. The raw material was aluminum 2-ethylhexanoate, which is nontoxic and easy to handle. At a reaction temperature above 480 °C, an amorphous film can be obtained on glass and silicon (100) substrates. The reaction temperature and the deposition rate are comparable to the corresponding values in the low-temperature chemical vapor depositions of Al2O3. In addition, the deposition can be carried out in air. Aluminum 2-ethylhexanoate appears to offer a viable alternative to alkylaluminum, aluminum β-diketonate, and alkoxide for low-temperature Al2O3 production.

Fluorine-doped tin dioxide thin films prepared by chemical vapor deposition

Transparent conductive tin dioxide thin films were prepared by a low-temperature atmospheric-pressure chemical vapor deposition method in air. The raw material was tin(II) trifluoroacetate. At a reaction temperature above 250 °C, polycrystalline thin films were obtained with a high deposition rate. This chemical vapor deposition method effectively incorporates F atoms into a crystalline structure and consequently maximizes the carrier concentration, yielding fluorine-doped SnO2 films of very low resistivity. For the 1260-nm-thick film deposited at 400 °C, the resistivity was 5.92×10−4 Ω cm, and the sheet resistance was 4.69 Ω/⧠. The deposition condition, structure, and characteristics of films were compared to the corresponding values in the chemical vapor depositions of SnO2 from tin(II) acetate.

Crystallization of amorphous silicon films using a multistep thermal annealing process

A multistep thermal annealing method, which utilizes the incubation time for nucleation to form large-grained polycrystals from seeded amorphous silicon film, was studied. According to this method, crystallization takes place in steps, via heating-cooling cycles. In each cycle the water is annealed for a period which is less than the incubation time for nucleation and then cooled to a low temperature for relaxation. During each annealing period, the seed grains grow to a certain extent, while spontaneous nucleation does not occur. Preliminary experimental results obtained with 0.17 μm thick amorphous films, which were deposited by the low pressure chemical vapor deposition method (at 818 K, 400 mTorr) on oxidized silicon substrates, exhibited general agreement with the basic idea of a multistep annealing process.

減圧ＣＶＤ法による超硬チップ上へのＨｆＣ‐（Ｈｆ・Ｔｉ）Ｃ‐ＴｉＣトリプルコーティング膜の生成及び耐摩耗性

Formation of wear resistance laminated HfC/TiC films on cemented carbide tools by low pressure chemical vapor deposition method were investigated.As a result, HfC- (Hf·Ti) C-TiC triply layered films with good adhesion were fabricated by inserting (Hf·Ti) C film between HfC and TiC films, and formation condition of triply layerd films was clarified. Layer structure of TiC film was found to depend on carbon content in TiC.The wear resistance characteristics of HfC- (Hf·Ti) C-TiC coated tools were found to be better than those of TiC coated tools. The mean flank wear, end flank wear, and crater wear of HfC- (Hf·Ti) C-TiC coated tools were smaller than those of TiC coated tools. However, the grooving wear of HfC- (Hf·Ti) C-TiC coated tools was almost same as that of TiC coated tools.