摘要:
A nickel-palladium alloy in the form of a layer is contacted by one portion of one main face of a semiconductor substrate to form a Schottky barrier. A gold layer is disposed upon the nickel-palladium layer and an electrically insulating film is disposed on the remaining portion of the one main substrate face to contact and surround both layers. The film has a thickness equal to or greater than the sum of thicknesses of both layers.BACKGROUND OF THE INVENTIONThis invention relates to a semiconductor device including a Schottky barrier and more particularly to means for thermally stabilizing electric characteristics of a Schottky barrier included in a semiconductor device.It is well known that the Schottky barrier is formed in semiconductors adjacent those portions thereof contacted by metallic members and there have been previously propsed many types of semiconductor devices utilizing the electric characteristics of the Schottky barrier. Some of such types of semiconductor devices have been already put to practical use and very frequently included the substrate of semiconductive material having disposed thereon the metallic layer formed of nickel. This nickel layer has been contacted by the substrate to form a Schottky barrier at the interface of the layer and substrate.Semiconductor devices of the type referred to are often used at fairly high temperatures and therefore it is desirable to maintain the electric characteristics of those semiconductor device unchanged even at fairly high temperatures. In other words, it is desirable to provide semiconductor devices of the type referred to be thermally stable in electric characteristics. It has been found that the Schottky barrier formed by contacting the nickel layer with the semiconductor substrate is thermally unstable in electric characteristics so that, when continuously subjectd to heat treatment in the atmosphere at 200.degree. C for one hour, the electric characteristics thereof have been considerably changed.The applicants have studied causes for which semiconductor devices having the Schottky barrier formed by contacting the nickel layer with the semiconductor substrate are changed in electric characteristics after they have been subject to heat treatment in the atmosphere. As a result, it has been estimated that one of the causes is to oxidize the nickel layer due to the heat treatment in the atmosphere. It is believed that this oxidation of the nickel layer will change the composition of the metallic layer and also the electric characteristics of the Schottky barrier. It has been also found that the oxidation of the nickel layer occurs with an additional layer of another metal such as gold covering the nickel layer in order to facilitate the bonding of an external lead to the nickel layer. In that event it has been estimated that oxygen diffused into the nickel layer through the additional layer oxidizes the nickel layer. Also it has been found that, with the additional metallic layer disposed upon the nickel layer, atoms of a metal forming the additional layer, for example, gold are diffused through the nickel layer into the semiconductor substrate due to the particular heat treatment. The diffused metallic atoms have reacted on the semiconductive material of the substrate. It has been estimated that this provides a second cause for which the Schottky barrier changes in electric characteristics. In addition, it has been found that, when thermally treated, the metal forming the additional metallic layer is alloyed with nickel forming the first layer. This alloying causes an increase in electric resistivity of the first layer and the occurence of strains in the crystal lattice of the first layer. Therefore it has been estimated that the alloying provides a third cause for which the Schottky barrier changes in electric characteristics.Although the second and third causes as above described offer no problem with semiconductor devices not including the additional metallic layer as above described, that layer has been, in many cases, provided on semiconductor devices including the Schottky barrier in order to make it possible to bond a lead to the device. Therefore the second and third causes are also important.It is an object of the present invention to provide a new and improved semiconductor device including a Schottky barrier thermally stable in electric characteristics by preventing any changes in the electric characteristics due to the causes as above described.Furthermore semiconductor devices of the type referred to are desirable to be small in a stray capacity relative to the Schottky barrier involved for the purpose of handling high frequency signals.Thus it is another object of the present invention to provide a new and improved semiconductor device including a Schottky barrier exhibiting the thermally stable electric characteristics and low in a stray capacity relative to the Schottky barrier.SUMMARY OF THE INVENTIONAccording to the principles of the present invention there is provided a semiconductor device comprising a substrate of semiconductive material, and a metallic member disposed on the substrate to be contacted by the latter thereby to form a Schottky barrier in the substrate adjacent that portion thereof contacted by the metallic member, the metallic member being composed of a nickel-palladium alloy.In order to decrease a stray capacity relative to the Schottky barrier, the semiconductor device may comprise preferably a substrate of semiconductor material including a pair of first and second main faces opposite to each other, a surface passivation film of electrically insulating material disposed so as to cover that portion of the first main face except for a predetermined portion thereof, a first metallic layer formed of a nickel-palladium alloy and disposed so as to contact the predetermined portion of the first main face thereby to form a Schottky barrier in the substrate adjacent that portion thereof contacted by the first metallic layer, and a second metallic layer disposed to cover the first metallic layer, the sum of the thickness of the first and second metallic layers not exceeding the thickness of the surface passivation film.
摘要:
A new platinum complex which has strong antitumor activity and has effect with smaller doses and a pharmaceutical composition containing the same are provided. A spiro[4,4]nonane-1,6-diamineplatinum(II) complex which is represented by a following general formula (A). (In the formula, X and Y are same or different, and X and Y represent halogen atoms respectively, or X and Y cooperatively represent a divalent residue which is described by a formula (Z).) The platinum complex has a strong antitumor activity and is efficacious as a therapeutic agent for malignant tumors.
摘要:
A liquid crystal display device comprising a liquid crystal display panel, a backlight and a heat sink member is disclosed. The backlight comprises a light-guiding plate disposed on one principal surface side of the liquid crystal display panel, LED light sources disposed on an end surface of the light-guiding plate, a mounting board for mounting the LED light sources thereon and a thermally conductive member connected to the mounting board. The heat sink member is connected to the mounting board through the thermally conductive member.
摘要:
A compound represented by the formula or a pharmaceutically acceptable salt thereof wherein R represents an unsubstituted pyridyl, furyl or thienyl group, or a pyridyl, furyl or thienyl group each of which has one or more substituents selected from the group consisting of a hydroxyl group, a lower alkoxy group, a hydroxy lower alkyl group and a hydroxy lower alkenyl group except that when the pyridyl, furyl or thienyl group has a lower alkoxy group as a substituent, each of which simultaneously has another substituent selected from the group consisting of a hydroxyl group, a lower alkoxy group, a hydroxy lower alkyl group and a hydroxy lower alkenyl group, m represents an integer of 1 to 3, and G represents a &bgr;-D-glucopyranosyl group, and the positions of substitution of the hydroxyl groups on the indolopyrrolocarbazole ring are the 1- and 11-positions, or the 2- and 10-positions, and an antitumore agent containing it as an effective ingredient. The compounds have a better antitumor action than known compounds having a similar structure.
摘要:
The present invention is a process for producing 3-methyl-2-oxoindoline as defined by the following chemical formula (2), including heating of propionylphenylhydrazide as defined by the following chemical formula (1) in the presence of at least one kind of basic calcium compound, characterized in that an organic solvent withstanding at least at a temperature of 180° C. in the presence of the basic calcium compound is employed by at least an amount of equal weight to that of the propionylphenylhydrazide. With the construction mentioned above, even when the amount of calcium oxide is reduced down to as little as 15% of a conventionally used amount, at least 75% of a corresponding yield attained conventionally has been achieved. That is, not only control of the reaction and easy after treatment but also a high yield has been achieved;
摘要:
This invention relates to compounds of the general formula ##STR1## or pharmaceutically salts thereof, wherein R.sup.1 and R.sup.2 each represent an OH group, R.sup.1 is located at the 1- or 2-position, R.sup.2 is located at the 10- or 11-position, R.sup.2 is located at the 11-position when R.sup.1 is located at the 1-position, and R.sup.2 is located at the 10-position when R.sup.1 is located at the 2-position. The compounds of the present invention have an excellent antitumor effect and are hence useful as antitumor agents in the field of medicine.
摘要:
Indolopyrrocarbazole derivatives represented by formula (I) and the pharmaceutically acceptable salts thereof have excellent antitumor activity as evidenced by their in vitro proliferation inhibiting activity against mouse leukemia cell, human gastric cancer cell, human lung cancer cell and human colon cancer cell, ##STR1## wherein R.sup.1 and R.sup.2 independently represent, for example, a hydrogen atom or various hydrocarbon groups which may be substituted or heterocyclic groups which may also be substituted; or a group --Y--R.sup.3 where Y represents a carbonyl group, thiocarbonyl group or sulfonyl group and R.sup.3 represents a hydrogen atom or one of various aliphatic, cycloaliphatic, aryl, nitrogen-containing (e.g. amino, hydrazino, etc) or heterocyclic groups, which groups may be substituted by various substituents; or R.sup.1 and R.sup.2 may combine to represent a lower alkylidene group which may be substituted; or R.sup.1 and R.sup.2, together with the N-atom to which they are bonded form a heterocyclic group which may be substituted;G represents a pentose or hexose group; and X.sup.1 and X.sup.2, independently, represent, for example, hydrogen, halogen, amino, hydroxyl, alkoxy, aryloxy, carboxyl, alkoxycarbonyl or alkyl. These compounds have improved water solubility as compared to rebeccamycin.
摘要:
A Schottky barrier semiconductor device comprising a semiconductor substrate having a hole in part of one of its main surfaces, a surface protecting film formed on the main surface and having a flange-like part extending over the edge of the hole, and a barrier metal formed on the entire wall of the hole including areas underneath the flange-like portion. The barrier metal film thus formed prevents concentration of an electric field at the edge of the interface between the barrier metal and the semiconductor substrate, thereby improving the reverse breakdown characteristics.
摘要:
New platinum(IV) complexes which has a strong antitumor activity and has a feature that a side effect is relatively reduced is provided. The new complex is platinum(IV) complexes with cis,cis-spiro[4,4]nonane-1,6-diamine ligand and is platinum(IV) complexes with optically active cis,cis-spiro[4,4]nonane-1,6-diamine ligand. Especially, the new complex is dichloromalonato((1S,5S,6S)-spiro[4.4]nonane-1,6-diamine)platinum(IV).
摘要:
A semiconductor device includes a gate pad, a gate wiring conductor connected to the gate pad, and a gate electrode formed under the gate pad and the gate wiring conductor. Portions of the gate electrode closer to the gate pad have a higher resistance per unit area than portions of the gate electrode farther away from the gate pad.