Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Mitsunori Nakatani

Hiroaki Morikawa

Shoichi Karakida

Takahiko Nishida

Hiroyuki Minami

Yoshiki Kojima

Hirofumi Nakano

Takahiro Ueno

Katsuya Kosaki

Masafumi Minami

Hisashi Tominaga

Kiyoshi Nishikawa

Yuichiro Hosokawa

Keizo Makino

Takayuki Fujii

Toshihiko Fujihara

A lower resist () is applied on a semiconductor substrate (). An upper resist () is applied on the lower resist (). A first opening () is formed in the upper resist () by exposure and development and the lower resist () is dissolved with a developer upon the development to form a second opening () having a width wider than that of the first opening () below the first opening () so that a resist pattern () in a shape of an eave having an undercut is formed. Baking is performed to thermally shrink the upper resist () to bent an eave portion () of the upper resist () upward. After the baking, a metal film () is formed on the resist pattern () and on the semiconductor substrate () exposed at the second opening (). The resist pattern () and the metal film () is removed on the resist pattern () and the metal film () is left on the semiconductor substrate () as an electrode ().

Method for manufacturing semiconductor device

A solar battery cell, including semiconductor substrate, an insulating film formed on one face side of the semiconductor substrate, and an electrode electrically connected to the one face side of the semiconductor substrate, the electrode being embedded in a groove that is provided on the insulating film and provided so as to protrude from a surface of the insulating film by a same width as the groove.

Solar battery cell and production method thereof

A method for producing a solar battery cell, includes: a first step of forming an insulating film on one face side of a semiconductor substrate; a second step of forming an electrode forming groove in an electrode forming region on the insulating film; a third step of printing an electrode printing paste including metal particles as a main component to a width that covers the electrode forming groove and a region sandwiching the electrode forming groove on the insulating film and that is wider than a width of the electrode forming groove, and then drying the electrode printing paste; and a fourth step of forming an electrode with the width of the electrode forming groove by firing the electrode paste at a temperature that is equal to or higher than a melting point of the metal particles or that is equal to or higher than a eutectic temperature, and accumulating and solidifying the electrode paste on the electrode forming groove.

The method includes: steps of forming an n-type diffusion layer having an n-type impurity diffused thereon at a first surface side of a p-type silicon substrate; forming a reflection prevention film on the n-type diffusion layer; forming a back-surface passivation film made of an SiONH film on a second surface of the silicon substrate; forming a paste material containing silver in a front-surface electrode shape on the reflection prevention film; forming a front surface electrode that is contacted to the n-type diffusion layer by sintering the silicon substrate; forming a paste material containing a metal in a back-surface electrode shape on the back-surface passivation film; and forming a back surface electrode by melting a metal in the paste material by irradiating laser light onto a forming position of the back surface electrode and by solidifying the molten metal.

Photovoltaic device and method for manufacturing the same

A solar cell comprises a substrate that includes a photoelectric conversion function, a first electrode provided on one surface of the substrate, a second electrode provided on other surface of the substrate, and a third electrode provided on the other surface of the substrate with its periphery overlapping the second electrode in the in-plane direction of the substrate for extracting an electric power from the second electrode. The thickness of the second electrode is larger than that of the third electrode, and the difference between the thickness of the second electrode and that of the third electrode is within a range from equal to or more than 10 micrometers to equal to or less than 30 micrometers. Thereby, in the solar cell, an electrode separation (alloy separation) can be effectively prevented.

Solar cell and manufacturing method thereof

A solar cell includes a photoelectric conversion layer, a first electrode on one surface of the photoelectric conversion layer, a second electrode provided on other surface of the photoelectric conversion layer, and a third electrode on the other surface of the photoelectric conversion layer. The third electrode is substantially rectangular with its corners rounded off in the in-plane direction of the photoelectric conversion layer, and overlaps the second electrode at the periphery thereof.

Solar cell

A printing stage includes a stage surface having a plurality of suction holes, and fixes an object to be printed on the stage surface by vacuum contact. A printing mask is employed for forming a predetermined electrode pattern on the object to be printed fixed to the printing stage. A squeegee applies a predetermined amount of pressure to a metal paste spread on the printing mask, to print the electrode pattern on the object to be printed. A porous body is provided between the object to be printed and the printing stage.

Screen printing machine and solar cell

A solar cell includes a photoelectric conversion substrate, a first electrode on one surface of the substrate, a second electrode on the other surface of the substrate, and a third electrode on the other surface of the substrate. The third electrode extracts electric power from the second electrode, and overlaps the second electrode at the periphery in the in-plane direction of the photoelectric conversion substrate. The thickness of the second electrode is larger than that of the third electrode, and the difference between the thickness of the second electrode and that of the third electrode is not less than 10 micrometers and not more than 30 micrometers.

A printing mask includes a mask frame and a mesh extended on the mask frame, in which a mask portion is formed by filling the mesh with resin to leave a pattern forming portion in a region corresponding to an electrode pattern to be formed on a printing object. The mask portion has a raised part on a surface of the mesh to be opposed to the printing object. The thickness of the raised part is such that a difference in average film thickness between the end and other parts of the electrode pattern formed with the printing mask is equal to or less thanmicrometers.

Printing mask and solar cell

A semiconductor device includes a circuit substrate having a first surface on which a high-frequency circuit is located; a first metal layer disposed on a second surface of the circuit substrate; bump wirings on the first surface of the circuit substrate and electrically connected to the high-frequency circuit; a metal wall disposed on the first surface of the circuit substrate surrounding the high-frequency circuit; a wiring substrate having one surface on which substrate wirings corresponding to the bump wirings are located, the wiring substrate being disposed on the circuit substrate so that the substrate wirings are electrically connected to the bump wirings, and in contact with the metal wall, sealing a region including the high-frequency circuit; and a second metal layer disposed on a second surface of the wiring substrate. An electromagnetic shielding effect sufficient for use in a high-frequency circuit is obtained and fabricating cost is considerably reduced.

Sealed semiconductor device including opposed substrates and metal wall

A semiconductor device includes a semiconductor substrate having first and second main surfaces; a function element layer having heating element portions generating heat during operation, disposed on the first main surface that is thinned; and a plated heat sink of a heat conductive material, having a thickness equal to or greater than that of the semiconductor substrate, disposed on a circumferential region of the second main surface at the perimeter of the semiconductor substrate inward, on main heat generating regions of the second main surface including regions opposite the heating element portions, and on supporting regions of the second main surface connecting the circumferential region to the main heat generating regions. The semiconductor device maintains the heat generating function and the handling performance of the plated heat sink, reduces internal stress during plating and repeated stress produced by heat cycles during fabricating processes, and lessens chip breakage and plating peeling.

Semiconductor device

A pattern transfer mask for use in an optical exposure process includes a transparent substrate having a surface; a light shielding film of a desired pattern disposed on the surface of the transparent substrate for shielding a part of a photoresist film from light transmitted through the mask and incident on the photoresist film and for transferring the desired pattern to the photoresist film; and a plurality of projections disposed at equal intervals on one side of and contacting the light shielding film pattern for reducing the intensity of light transmitted through the transparent substrate where the projections are present.

Pattern transfer mask

In a method for producing a field effect transistor, a positive photoresist is deposited on a surface of a semiconductor substrate, the positive photoresist is exposed to light having an asymmetric intensity profile where a gate electrode is to be formed, the positive photoresist is converted into a negative photoresist, the negative photoresist is developed to form a pattern having an aperture opposite the gate electrode formation region of the substrate and asymmetric overhanging portions at the aperture, the semiconductor substrate is wet etched using the photoresist pattern as a mask to form a recess in the semiconductor substrate, and a gate metal is deposited using the photoresist pattern as a mask to form a gate electrode in the recess. Therefore, only one exposure process provides a photoresist pattern having asymmetric overhanging portions at the aperture of the pattern.

Method for producing field effect transistor

A phase shift mask having a phase shifter with an edge angle ranging from 70.degree. to 85.degree. or 95.degree. to 110.degree. is used as a reticle in forming a resist pattern so that the exposure pattern applied to the resist has a light intensity distribution with constant light intensity contrast. A fine resist pattern having a predetermined width no more than the wavelength of the light used to form the pattern is produced precisely and reproducibly under constant developing conditions. In addition, there is provided on the side wall of the phase shifter of the phase shift mask a light shielding film which, due to its width, cannot be resolved as an exposure pattern itself. A region in which the light intensity is reduced from the constant level corresponding to the width of the light shielding film in the exposure pattern is formed by the projection lens. Therefore, a fine resist pattern having a predetermined width no more than the wavelength of the light used to form the pattern is produced precisely and reproducibly using constant developing conditions. As a result, semiconductor devices with good performance can be manufactured with high yield.

Method for forming resist pattern

A method of manufacturing a field effect transistor comprises sequentially epitaxially growing on a semi-insulating compound semiconductor substrate an active layer of the first compound semiconductor having a first dopant concentration and a source layer of the first compound semiconductor having a second dopant concentration higher than the first dopant concentration, removing part of the source layer to leave a source region on the substrate, forming a gate electrode on the active layer spaced from the source region, forming a drain region in the substrate spaced from the gate electrode, on the opposite side of the gate electrode from the source region, adjacent to and in contact with the active layer and having a dopant concentration intermediate the dopant concentrations of the active layer and the source region, and forming source and drain electrodes on the source and drain regions, respectively.

Growing community of inventors

Tokyo, Japan

Mitsunori Nakatani