Shin-etsu Handotai Co., Ltd.

Seh America, Inc.

Masami Nakano

Isao Uchiyama

Hisashi Masumura

Hideo Kudo

Hiroyuki Takamatsu

Tadahiro Kato

Morie Suzuki

Sunao Shima

Jim Woodling

Takao Abe

Michito Sato

Toshio Ajito

Hiroyuki Takamatu

Brian D West

Jaclyn N Danh

A system for conditioning an alkaline etching solution for reducing contamination in a silicon wafer etching process. The system includes a conditioning tank for mixing a conditioned alkaline etching solution, the conditioned alkaline etching solution including a conditioning chemical; a conditioning chemical introduction system configured to add the conditioning chemical to the conditioning tank; and a buffer tank for storing the conditioned basic etching solution before using the conditioned alkaline etching solution in an etching process.

System for reducing wafer contamination using freshly, conditioned alkaline etching solution

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

Methods for drying semiconductor wafers following a chemical cleaning process utilize both a hot deionized water bath and medium-wavelength infrared light drying techniques. A preferred method comprises the steps of (a) maintaining a body of hot deionized water in a bath; (b) submerging multiple wafers to be dried in the body of hot deionized water in said bath; (c) slowly pushing said multiple wafers up through the surface of the body of hot deionized water in said bath; (d) providing an infrared bath containing an infrared lamp; and (e) transferring said multiple wafers to said infrared bath for drying.

Method of drying semiconductor wafers using hot deionized water and

A method of preventing edge stain in silicon wafers from the edge polishing step with an alkaline slurry, the method consisting of formation of an oxide layer by an ozone dipping step prior to edge polishing.

Prevention of edge stain in silicon wafers by ozone dipping

A method of polishing semiconductor wafers includes a double side primary polishing step and a single side secondary polishing step using a single side polishing machine with a wafer holder including a template so bonded on a carrier plate as having one or more wafer receiving holes in which backing pads are disposed respectively for holding the back sides of the respective wafers fittingly received therein. This method makes it to possible to hold a plurality of wafers at one time due to batch processing to thereby improve the productivity, and decrease extremely the generation of the defective dimples in the front side of the wafer. Compared with conventional single side polishing, the flatness level of the wafer polished with the double side polishing machine in this method is improved.

Method of polishing semiconductor wafers

A method of preventing edge stain in silicon wafers from the edge polishing step with an alkaline slurry, the method consisting of formation of an oxide layer by an annealing step in the presence of oxygen prior to edge polishing.

Prevention of edge stain in silicon wafers by oxygen annealing

A method for inducing damage for gettering to the rear surface of a single crystal silicon wafer by polishing the rear surface, which can provide a good gettering effect to the wafer and can also depress dusting characteristics of the rear surface of the wafer, is disclosed. The method comprises the steps of; moving the wafer on an abrasive cloth relatively, and supplying an abrasive liquid having a pH in the range of 4-9 which contains silica particles having an average diameter in the range of 0.1-10 .mu.m as abrasive grains, between the wafer and the abrasive cloth.

Method for inducing damage for gettering to single crystal silicon wafer

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

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 method for a flatter semiconductor wafer free of ORP-observed irregularity and particles generated in handling on the back side of the wafer, in which an alkaline etching is adopted to utilize its advantage and a slight polishing step is combined to a conventional method of this kind. A deficiency of alkaline etching which brings about rougher surface irregularities on the surface of a wafer is eliminated by the use of the step of slight polishing on the back surface after the etching step and the inherent advantage stands without a loss, so that particle generation from the back surface of a semiconductor wafer in handling is much reduced and what's more a flatter semiconductor wafer is realized and a yield of an electronic device fabrication is increased.

Method of making semiconductor wafers

A wafer which allows manufacture of a device to proceed at an exalted yield by preventing the resolution of exposure at the step of photolithography during the manufacture of the device from being impaired is obtained by a method which comprises a slicing step for slicing a single crystal ingot thereby obtaining wafers of the shape of a thin disc, a chamfering step for chamfering the wafer obtained by the slicing step, a lapping step for imparting a flat surface to the chamfered wafer, an etching step for removing mechanical strain remaining in the lapped wafer, an obverse surface-polishing step for polishing one side of the etched wafer, and a cleaning step for cleaning the polished wafer, which method is characterized by interposing between the etching step and the obverse surface-polishing step a reverse surface-preparing step for preparing the shape of the reverse side of the wafer.

Method for production of wafer

A method of inspecting bonded wafers, which involves obtaining a Lang topograph of bonded wafers as a sample by using a Lang camera, or further treating an image thereon, thereby detecting unbonded regions at the interface of the bonded wafers. In bonding two silicon wafers to each other, an one-side surface of each silicon wafer is finished into a mirror surface and then is cleaned to a sufficient extent. Subsequently, both the mirror surfaces of the two silicon wafers are superposed one upon the other and then the superposed wafers are subjected to high-temperature heat treatment. The high-temperature heat treatment is conducted mainly for the purpose of removing distortions on the bonded surfaces, making the bonding interface monolithic, and, absorbing and diffusing a very small amount of atmospheric gas.

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Vancouver, WA, United States of America

Masami Nakano