Shin-etsu Handotai Co., Ltd.

Semiconductor Components Industries, LLC

Other

Sanyo Semiconductor Co., Ltd.

Takeshi Arai

Akira Suzuki

Tadaaki Honma

Hitoshi Habuka

Yutaka Ohta

Hiroki Ose

Tomosuke Yoshida

Yuuji Nagahashi

Akira Hoshikawa

Satoshi Inada

Yusho Hoshina

Kenji Akiyama

Yukio Furugori

Tsutomu Shimazaki

Carry out a vapor etching step of cleaning an inside of a chamber of a vapor phase growth apparatus by vapor etching using HCl gas (S). Carry out an annealing step of sequentially annealing a predetermined number of silicon wafers, one by one, in a non-oxidizing atmosphere (S, S). Repeat the vapor etching step and the annealing step a prescribed number of times. After having carried out the vapor etching step and the annealing step the prescribed number of times (S: Yes), collect contaminants on the surface of each of the wafers, and measure the Mo concentration using ICP-MS (S). Evaluate the cleanliness of the vapor phase growth apparatus on the basis of each Mo concentration value and the relationship between the Mo concentrations (S). Thus, provided is a method with which it is possible to measure, with high sensitivity, the contamination amount of a vapor phase growth apparatus.

Method of measuring contamination amount of vapor phase growth apparatus, and method of manufacturing epitaxial wafer

A motor drive circuit includes: a digital filter configured to attenuate amplitude in a frequency band including a resonance frequency of an actuator in a target current signal, the target current signal being a digital signal indicative of a target value of a drive current, the drive current being supplied to a voice coil motor configured to drive the actuator; a digital-analog converter configured to convert an output signal of the digital filter into an analog signal, and output the converted analog signal as a current control signal; and a drive circuit configured to supply the drive current to the voice coil motor according to the current control signal.

Selection circuit with digital filter for VCM

A motor-drive circuit includes: a filter circuit to attenuate a frequency band including a resonance frequency of an actuator in a target-current signal, which is a digital signal indicating a target value of a driving current to be supplied to a voice-coil motor that drives the actuator; a digital-analog converter to convert an output signal of the filter circuit into an analog signal, to be outputted as a current-control signal; and a driving circuit to supply the driving current to the motor in accordance with the current-control signal, the filter circuit including: a digital-notch filter to attenuate a frequency band around the resonance frequency in the target-current signal; and a digital-low-pass filter to attenuate a frequency band greater than or equal to a predetermined frequency in the output signal of the digital-notch filter, the digital-low-pass filter having a sampling frequency higher than a sampling frequency of the digital-notch filter.

Motor drive circuit

A motor-drive circuit includes: a filter circuit to attenuate a frequency band including a resonance frequency of an actuator in a target-current signal, the target-current signal corresponding to a digital signal indicative of a target value of a driving current; a digital-analog converter to convert an output signal of the filter circuit into an analog signal, to be outputted as a current-control signal; and a driving circuit to supply the driving current to the voice-coil motor in accordance with the current-control signal, the filter circuit including: a digital notch filter; and a digital low-pass filter, wherein either one of the digital notch filter and the digital low-pass filter configured to be inputted with the target-current signal, the other one of the digital notch filter and the digital low-pass filter configured to be inputted with an output signal of the one of the digital notch filter or the digital low-pass filter.

A light-emitting element driving circuit includes a PWM signal output circuit configured to output a plurality of PWM signals each having one logic level whose duty ratio corresponds to gradation data and each corresponding to each of a plurality of light-emitting elements, on the basis of the gradation data indicating brightness of each of the plurality of light-emitting elements. A driving signal output circuit is configured to change the duty ratio of each of the plurality of inputted PWM signals to output the plurality of changed PWM signals as a plurality of driving signals, on the basis of instruction data for changing the brightness of the plurality of light-emitting elements. A driving circuit is configured to drive the plurality of light-emitting elements on the basis of a duty ratio of each of the plurality of driving signals.

Light-emitting element driving circuit

Provided is a method for manufacturing a silicon epitaxial wafer by growing an epitaxial layer by placing a silicon substrate on a susceptor. The method includes at least a step of forming a silicon oxide film entirely on the rear surface of the silicon substrate; a step of removing the silicon oxide film formed at least on an edge section of the silicon substrate; and a step of placing the silicon substrate on the susceptor with the silicon oxide film in between. An epitaxial layer is grown on the silicon substrate, while holding the silicon substrate by the susceptor with the silicon oxide film in between. Thus, the silicon epitaxial wafer by which generation of particles can be reduced in a device manufacturing process and a method for manufacturing such silicon epitaxial wafer are provided.

Silicon epitaxial wafer and manufacturing method thereof

A susceptor () supporting a semiconductor substrate (W) in a vapor phase growth, wherein a pocket () is formed on an upper surface of the susceptor to arrange the semiconductor substrate (W) inside thereof. The pocket () has a two-stage structure having an upper stage pocket () for supporting an outer peripheral edge portion of the semiconductor substrate (W) and a lower stage pocket () formed on a lower stage of a center side from the upper stage pocket (). A hole () penetrated to a rear surface of the susceptor and opened in the vapor phase growth is formed in the lower stage pocket ().

Susceptor, vapor phase growth apparatus, epitaxial wafer manufacturing apparatus, epitaxial wafer manufacturing method, and epitaxial wafer

In an apparatus for vapor phase growth of silicon single crystal thin films, in-plane uniformity of susceptor temperature is improved and film thickness of a silicon single crystal thin film is uniformized. The base material of a lift pin provided in a pocket of a susceptor is changed to a base material lower in thermal conductivity than a base material of the susceptor , by which local decreases in susceptor temperature in the vicinity of the lift pin are prevented. As the base material of the lift pin , SiC, carbon of a desired grade and quartz are preferred.

Apparatus for thin film growth

A surface roughness distribution in the surface of a silicon epitaxial wafer is made uniform by optimizing a temperature distribution in the surface of a susceptor used in a vapor phase thin film growth apparatus. The susceptor is not supported by its center of the rear surface thereof, but only the peripheral portion thereof is supported using vertical pins respectively provided at the far ends of spokes radially branched from a rotary shaft. The susceptor is constituted so that a difference in temperature between the maximum and minimum in the surface of a silicon wafer is suppressed to a value equal to or less than 7&deg; C. Hence, a surface roughness distribution in the surface of the silicon epitaxial wafer can be suppressed to a value equal to or less than 0.02 ppm.

Silicon epitaxial wafer and production method therefor

An automotive window molding attached onto a circumference of a window glass and arranged at a pillar side of a vehicle body, includes an outside glass abutting portion being in contact with an outside surface of the window glass, an outside ornamental head portion arranged outside of the outside glass abutting portion and spaced apart from the outside glass abutting portion so that the outside ornamental head portion and the outside glass abutting portion are opposed to each other, and a connecting wall portion interconnecting the outside ornamental head portion and the outside glass abutting portion. A drip groove is defined by the outside glass abutting portion, the outside ornamental head portion, and the connecting wall portion, so that the drip groove is opened toward inside of the perimeter of the window glass. In order to allow snow to impinge and break on a tip of the outside glass abutting portion by wiping action of a wiper blade during vehicle driving in the snow, a tip portion of the outside glass abutting portion is configured to protrude toward inside of the perimeter of the window glass more than a tip portion of the outside ornamental head portion protrudes toward inside of the perimeter of the window glass.

Automotive window molding

A method of making a sample in a form of an outline drawing sheet, comprises the steps of preparing a plastic sheet,used for a base member, a screen for screen-printing, having a screen mesh,corresponding to a border line,for an outline drawing sheet, and a squeegee; placing printing ink,on the screen with the screen closely contacted to the plastic sheet; squeezing out the printing ink,through the screen mesh,by using the squeegee,to print a frame,constituting the border line for the outline drawing sheet,on the plastic sheet; applying paint,having a desired color on the plastic sheet,at an inside of the frame,after the frame,has been cured, to thereby form a colored portion,and stripping the frame,and the colored portion,integrated with the frame,, from the plastic sheet

Method of making sample in form of outline drawing sheet

A method of casting-masking-molding a thermoplastic resin product, includes the steps of placing a molding sheet 1 on an upper surface of a heated table plate 4, the molding sheet including a molding die 2, and a mask 3 including a plurality of mask constituting pieces 3a, 3b, 3c, ... which are fitted into the molding die and capable of being separated from one another, filling the molding die 2 of the molding sheet 1 in order by pouring a thermoplastic resin liquid 6a of a desired color into a portion of the mask 3 from which one of the mask consisting pieces is taken out, then to solidify the poured thermoplastic resin liquid, and repeating in a required number of times the steps of pouring a thermoplastic resin liquid 6b of the same color as the desired color or another color different therefrom into another portion of the mask from which another of the mask constituting pieces is taken out, then to solidify the poured thermoplastic resin liquid, and further heating the molded resin body 6 placed on the table plate 4, which is separated from the molding sheet 1 and placed on the table plate 4, and gelatinizing the molded resin body, thereafter to cool the molded resin body.

Method of casting-masking-molding thermoplastic resin product

A cylindrical apparatus for the growth of epitaxial layers having disposed inside a bell jar a susceptor provided thereon with pockets for retaining a substrate is disclosed. It allows the flow rate of a raw material gas inside the apparatus to be uniformized, the fluctuation of film thickness of epitaxial layers within one batch to be repressed below 5%, and the fluctuation of film thickness of an epitaxial layer in the substrate to be decreased by equalizing the gap area between the peripheral surface of the susceptor and the internal wall surface of the bell jar at least in the lateral wall portions of the bell jar confronting the substrates on the susceptor.

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Gunma, Japan

Takeshi Arai