Hideo Sawai

Plasma Etching of ITO Thin Films Using a CH4/H2 Gas Mixture

Plasma etching of ITO (In2O3:Sn indium tin oxide) thin films has been performed using a CH4/H2 plasma. Etching occurs above a substrate temperature (Ts) of 60°C and the etch rate increases with increasing Ts, while amorphous like or polymer-like carbon deposits onto the ITO films below 60°C. The apparent activation energy of the etching is 4.12 kcal/mol (0.18 eV). This small activation energy suggests that the desorption of produced volatiles is the rate-limiting process. Fine ITO patterns (1.5 µmL/S) were obtained using this gas mixture.

Effect of Phosphorus Content of the Magnetic and Electric Properties of Electroless Ni–P Film after Heat Treatment

The magnetic and electric properties of electroless Ni–P films after heat treatment are investigated as a function of the P content in the deposit. The residual Ni, which means the surplus Ni (crystallized Ni) after Ni3P formation, is confirmed to determine the film properties of resistivity and saturation magnetization. Moreover, they depend only on the P content and are independent of the preparation conditions. The saturation magnetization, Ms, and the reciprocal of resistivity, ρ-1, are proportional to the amount of the residual Ni after sufficient heat treatment. An equation, showing the correlation between the P content and the resistivity or magnetization of the deposit after sufficient heat treatment, is proposed on the basis of the characters of ferromagnetic and metallic conductivity of the residual Ni matrix.

Behavior of Pd/Sn and Pd Catalysts for Electroless Plating on Different Substrates Investigated by Means of Rutherford Backscattering Spectroscopy

Principe de la spectroscopie de retrodiffusion. Resultats montrant que le comportement de ces systemes catalytiques dans des bains de Ni-P et Ni-P-W depend beaucoup du substrat

Very-Low-Temperature Preparation of Poly-Si Films by Plasma Chemical Vapor Deposition Using SiF4/SiH4/H2 Gases

Polycrystalline-Si (poly-Si) films have been prepared on glass substrates (Corning 7059) at a very low temperature (300°C) by conventional plasma chemical vapor deposition (plasma CVD) using SiF4/SiH4/H2 gases. The crystallinity was characterized by X-ray diffraction, reflection high-energy electron diffraction (RHEED), transmission electron microscopy (TEM) and Raman spectroscopy measurements. The effect of the SiH4 flow rate on crystallization proved to be large. The films indicated a strong -preferred orientation. The crystalline fraction was estimated to be more than 80%. The average and maximum grain sizes were estimated to be 60 nm and 130 nm, respectively.

A Study on the Low Energy Consumption Thermal Head Using Electroless Ni‐W‐P Alloy Films as Heating Resistors

The new head, composed of screen-printed polyimide resin with SiC powder (10 μm thick) as the protective layer, an electroless Ni-W-P film (0.25 μm thick) as the heating element, a polyimide film (50 μm thick) as the heat-insulating layer. The new head produces the good printing quality with 60% of the power required by the conventional one

Characteristics of Cr Schottky amorphous silicon photodiodes and their application to linear image sensors

Cr Schottky amorphous silicon (a-Si:H) photodiodes with a configuration of Cr/a-Si:H tin-doped indium oxide (ITO), where Cr is negatively biased with respect to ITO in contrast to the conventional bias direction, were characterized to provide simple and stable sensor elements for economical linear image sensors. It was found that the barrier height of the Cr/a-Si:H junction is sufficiently high (0.89 eV) to prevent electron injection and that the junction is thermally stable. The transport properties of holes propagating in the a-Si:H layer were largely improved by a few parts per million boron doping, and as a result saturation of the photocurrent was achieved. A contact-type ISO A4, 8-dot/mm linear range sensor was fabricated using the Cr Schottky photodiode array. The sensor showed excellent characteristics for use in G3 facsimile. >

A study of binders for the thick-film cathodes of DC-type plasma display panels

This paper reports work done on developing binders for thick-film cathodes used in DC-type plasma display panels (PDPs). Instead of the conventional lead glass binder, this paper proposes a new liquid binder consisting of a liquid that can be mixed with a fine powder to form a paste. This paste can be baked in an irreversible process to form a solid that is highly resistant to both heating and reduction. Of the possible candidates, the partially hydrolyzed condensate of tetraethoxysilane (having an average degree of polymerization of 6) was selected to be used as a post-sintering binder for SiO/sub 2/. By using this binder in the manufacture of thick-film Ca/sub 0.2/La/sub 0.8/CrO/sub 3/ cathodes, the deterioration of the electrical characteristics of the color PDPs and the changing composition of the gas will slow, leading to longer product lifetime. MgO, ITO, and SnO/sub 2/ prepared using similar methods also produced potent binders. Thus some liquid binders are promising for application as the binder for thick-film cathodes used in DC-type PDP. >

Direct-contact type image sensors using a novel amorphous-silicon photodiode array

A novel type of amorphous-silicon (a-Si:H) photodiode array for direct-contact type (lens-less) line image sensors was developed. A U-shaped top ITO (tin-doped indium oxide) contact and a rectangular a-Si:H window resolves the accumulation of dust from the documents at the steps of the light window. Semi-insulating Al-Si-N and insulating SiN/sub X/ stacked films are successfully applied to the surface protection layer to prevent a charge buildup by friction with documents.<<ETX>>

Density-of-states determination of amorphous silicon from space-charge-limited photocurrents

The density‐of‐states around midgap g(E) of undoped amorphous silicon (a‐Si:H) has been determined by measuring the space‐charge‐limited photocurrent (SCLPC) of a‐Si:H Schottky diodes under blue light (λ=450 nm) illumination. In this novel technique, a single type of photogenerated carrier is utilized as the source of space charge to dispense with highly doped layers required in the conventional space‐charge‐limited current (SCLC) technique. Conditions for the uniform formation of space charge are discussed and checked by the satisfaction of a scaling law for samples with different thicknesses. The g(E) deduced from the SCLPC is found to be similar to that from the SCLC technique.

Microstructures in Large Area Devices

電子機器 の小型.高 性能化 が進 む中で電子部 品 も,よ り小型 にさ らにまた,従 来2~3個 の部品 で構成 されて いた機能を1個 の部品で機能す るよ うになってきている。 それ に伴 い,加 工技術 も平面 のみな らず立体的 に も高精 細,高 密度 なものが要求 されて いる。 電子部品 の小型化が要求 され る中で,製 品 と して必 ず あ る程度の長 さ,面 積が必要 な ものが ある。 それは,印 字,画 像を担当す る出力部分で ある。具体的 には,ラ イ ンプ リンタのヘ ッ ド部品 とディスプ レイ部品で ある。 こ れ らは,人 がその まま見 るための大 きさを備え ていなけ ればな らず,よ り軽 く,薄 くと言 う要望 はあ って もよ り 小 さくと言 う要望 はな くむ しろより大 きなものが求 め ら れてい る。例 えば,プ リン トヘ ッ ドで は紙の幅 と して良 く使用 する,A4判(横210mm),B4判(257mm) の ものか らAO判(横841mm)ま で,デ ィスプ レイ デ バイスでは,直 接見 るもの と して対 角線 の長 さ10イ ン チ(254mm)さ らに40イ ンチ(約1m)の もの まで あ る。 本稿 ではこれ ら長 い,ま た面積 が大 きいデバ イスにお ける微細加工技術 についてその一部 を紹介 す る。