Shin-etsu Handotai Co., Ltd.

Isao Uchiyama

Hideo Kudo

Masami Nakano

Hiroyuki Takamatsu

Morie Suzuki

Yoshiharu Kimura

Toshio Ajito

Takashi Tanakajima

Fumihiko Hasegawa

Kouichi Tanaka

Masayuki Yamada

Makoto Tsukada

Hiroyuki Takamatu

A method of purifying an alkaline solution is capable of extremely efficiently nonionizing metallic impurity ions in an alkaline solution at a low cost. A method of etching semiconductor wafers in turn is capable of etching semiconductor wafers using the purified alkaline solution without deteriorating the quality of the semiconductor wafers. A reducing agent having an oxidation potential lower than a reversible electrode potential of metallic ions existing in the alkaline solution is dissolved in the alkaline solution to thereby nonionize the metallic ions existing in the alkaline solution.

Method of purifying alkaline solution and method of etching semiconductor wafers

A method of purifying an alkaline solution includes dissolving metallic silicon and/or silicon compounds in the alkaline solution and non-ionizing metallic ions in the alkaline solution with reaction products generated when the metallic silicon and/or silicon compounds are dissolved therein. This purifying method is capable of remarkably decreasing metallic ions in the alkaline solution at a low-cost by an easy operation. A method of etching semiconductor wafers includes purifying an alkaline solution by non-ionizing metallic ions in the alkaline solution and etching the semiconductor wafers by using the purified alkaline solution. According to this etching method, the metallic contamination level due to the etching of the semiconductor wafers is greatly decreased, there being neither deterioration in the wafer quality nor deterioration in the characteristic of the semiconductor device.

Method of purifying alkaline solution and method of etching

A method for cleaning a semiconductor silicon wafer, which can suppress and reduce adhesion of particles to the surface of the wafer, is disclosed. The method includes the steps of cleaning the semiconductor silicon wafer by using hydrofluoric acid aqueous solution containing a surfactant, and thereafter rinsing the semiconductor silicon wafer by using pure water containing ozone.

Method for cleaning semiconductor silicon wafer

A novel HF cleaning method of silicon wafers is provided whereby the wafers are cleaned with a lowered level of particle contamination on the surface thereof. In the method silicon wafers are immersed in a HF bath, followed by immersion in a deionized water bath. The silicon wafers are lowered into and lifted out of each bath along a direction which is substantially vertical with respect to a surface of each bath at a rate of from 1 mm/sec to 50 mm/sec. During immersion, a vertical oscillation of the surface of each bath is maintained in the range of less than 4 mm.

Method of cleaning silicon wafers in cleaning baths with controlled

A method of inspecting particles on wafers is disclosed, wherein a first particle map is made by particle measurement on a wafer to be inspected, then a particle removing treatment is conducted to remove particles from the wafer, subsequently after a second particle map is made by particle measurement on the wafer which is subjected to the particle removing treatment, the first particle map is compared with the second particle map, and particles appearing at the immobile point common in both the first particle map and the second particle map are determined as crystal defects or surface irregularities such as scratches and particles appearing in the first particle map but those disappearing in the second particle map are determined as real dust particles or contaminants, thereby accurately detecting particles on wafers.

Method of inspecting particles on wafers

An improved semiconductor wafer cleaning method capable of cleaning wafers without degrading the surface roughness of the wafers includes the steps of cleaning a polished wafer with an aqueous solution of hydrofluoric acid, then rinsing the wafer with ozone-containing water, and thereafter brush-scrubbing the wafer.

Method of cleaning semiconductor wafers

The present invention provides a device for handling wafers with every group of more than one that is built in a cassette-less automatic wafer cleaning apparatus, wherein the group of wafers are washed at a time which does not require very high accuracy in positioning the wafers and may accommodate the wafers of any different diameters, the device for handling wafers comprising: external hollow shafts and internal shafts inserted and freely slidable within the inside of the external hollow shafts; a drive mechanism, wherein each pair of the external hollow shafts and the internal shafts are movable in their respective opposed directions by the same distances with a timing belt and a drive motor for driving the timing belt; a pair of handling members respectively held fast at pairs of ends side by side of each pair of the external hollow shafts and the internal shafts; and a plurality of supporting structures holding the wafers provided on the respective opposed surfaces of handling members.

Device for handling wafers

A brush cleaning apparatus which includes at least one brush cleaning means having a pair of rotary brushes that are arranged in parallel one above the other. Disk-shaped objects are transported one at a time between the brushes so as to be cleaned thereby. A stopper is provided in front of the disk-shaped objects. The stopper selectively blocks movement of the disk-shaped objects and releases the disk-shaped objects for controlled movement of the disk-shaped objects through the cleaning apparatus.

Brush cleaning apparatus and cleaning system for disk-shaped objects

A wafer holder for handling wafers, particularly during a vapor drying process during automated wafer processing, provides for change of the diameter of the wafers to be held without replacement of one wafer holder with another in a wafer processing apparatus. The wafer holder is a unitary structure having a plurality of wafer holding portions, each wafer holding portion having a geometry appropriate to a single wafer diameter which differs from the diameter of wafers to be held by other wafer holding portions of the unitary structure. The wafer holder is preferably secured onto a robot arm in the wafer processing apparatus and can be rotated in orientation by a mechanical linkage in the robot arm in order to receive and hold wafers of a specific diameter being processed in the wafer processing apparatus at any given time. When wafers of another, different, diameter are to be processed, the unitary structure is rotated, preferably in an automatic fashion, to rapidly present a geometry of another wafer holder portion appropriate to the new wafer diameter by bringing the wafer holder to a changed orientation.

Wafer holder

A method for handling wafers one at a time for processing without the necessity for transporting the wafers in a carrier such as a wafer cassette or basket. After a manufacturing step such as a polishing step, the wafers are carried to a loader assembly in a horizontal orientation under the influence of flowing liquid. The wafers are then individually erected into a vertical orientation by being first stopped by stopper pins which stand vertically on a wafer receiving plate of a suction arm including a suction nozzle which firmly holds the wafers while the arm is pivotally rotated until the wafer is positioned into a vertical orientation. The vertical orientation thus achieved allows the wafer to be gripped by a wafer gripping portion of a transportation robot including grooved gripping arms operated by a mechanism which limits the force applied to the wafer. Cleaning baths include an arrangement for supporting wafers in a near vertical orientation and nozzles which direct cleaning liquids in a direction tending to prevent floating of the wafers. A brush cleaning bath provides for simultaneous cleaning of both sides of the wafer with rotatory brushes during which the wafer is supported vertically and made to move circumferentially by rollers while periodic vertical motion between the wafer-supporting rollers and the brushes is achieved with a drive motor and ball screw. A drying bath using infrared light completes the cleaning procedure before the wafers are loaded into an unloader assembly into which wafer cassettes are set.

Method for handling or processing semiconductor wafers

A wafer cleaning tank including a tank body containing therein a cleaning solution, and wafer supporting device for substantially vertically supporting at least one wafer in the tank body, wherein the wafer supporting device includes a pair of confronting fixed wafer support members disposed in the tank body with a predetermined space therebetween and each having at least one side wafer-supporting portion, and a movable wafer support member vertically movably disposed centrally between the fixed wafer support members at a level below the fixed wafer support members and having at least one central wafer-supporting portion corresponding in position to the position of the side wafer-supporting portion of each of the fixed wafer support members, and wherein the side wafer-supporting portions and the central wafer-supporting portion jointly form a three-point support structure which supports the wafer at three points on the outer edge thereof. The wafer cleaning tank thus constructed is capable of cleaning a plurality of wafers at one time and well adaptable to the cleaning of wafers of different diameters.

Wafer cleaning tank

An automatic cleaning apparatus cleans wafers one at a time without the necessity for transporting the wafers in a carrier such as a wafer cassette or basket. After a manufacturing step such as a polishing step, the wafers are carried to a loader assembly in a horizontal orientation under the influence of flowing liquid. The wafers are then individually erected into a vertical orientation by being first stopped by stopper pins which stand vertically on a wafer receiving plate of a suction arm including a suction nozzle which firmly holds the wafers while the arm is pivotally rotated until the wafer is positioned into a vertical orientation. The vertical orientation thus achieved allows the wafer to be gripped by a wafer gripping portion of a transportation robot including grooved gripping arms operated by a mechanism which limits the force applied to the wafer. Cleaning baths include an arrangement for supporting wafers in a near vertical orientation and nozzles which direct cleaning liquids in a direction tending to prevent floating of the wafers. A brush cleaning bath provides for simultaneous cleaning of both sides of the wafer with rotatory brushes, during which the wafer is supported vertically and made to move circumferentially by rollers while periodic vertical motion between the wafer-supporting rollers and the brushes is achieved with a drive motor and ball screw. A drying bath using infrared light completes the cleaning procedure before the wafers are loaded into an unloader assembly into which wafer cassettes are set.

Automatic cleaning apparatus for wafers

A scrubber cleaner for cleaning the unsucked face and peripheral chamfers of a semiconductor wafer. A wafer holder capable of holding the wafer by vacuum suction and turning the wafer circumferentially, and including a wafer suction head for fixing the wafer on it and a motor to rotate the suction head. A brush assembly including a rotatory plate having a brushing surface on one side consisting of a flat ring portion and a side-of-cylinder portion, and being capable of shifting axially and in radial directions; a motor for rotating the rotatory plate circumferentially; an air cylinder for shifting the rotatory plate axially; and another air cylinder for shifting the rotatory plate in radial directions. The side-of-cylinder portion of the brushing surface axially extends from the inner boundary of the ring portion, and the rotatory plate is disposed such that the flat ring portion of the brushing surface of the brush is opposed to and in parallel to the unsucked face of the wafer which is held on the suction head.

Scrubber apparatus for cleaning a thin disk work

A polishing apparatus for polishing an object to be polished at a high flatness includes at least one plate with at least one object to be polished secured at an underside thereof, a head section surrounding the plate with a predetermined gap therebetween, a pressure applying device for applying a pressing force to the top of the plate, and a holding device for holding the plate in the plane of the polishing movement of the object to be polished. The pressure applying device and the holding device are both disposed in an inner space of the head section, the latter being movable perpendicular to the plane of the polishing movement. The attaching position of the holding device on the outer surface of the plate is set substantially at the same height as or at a position lower than the attaching position of the holding device on the inner surface of the head section. The intersecting point of the imaginary lines through the fixing positions of the holding device on the head section and those corresponding to them on the plate substantially lies on or at a position lower than the polishing surface of the object to be polished.

Growing community of inventors

Fukushima-ken, Japan

Isao Uchiyama