Sumco Corporation

Sumitomo Mitsubishi Silicon Corporation

Sakae Koyata

Kazushige Takaishi

Katsuhiko Murayama

Tomohiro Hashii

Takeo Katoh

Tohru Taniguchi

Kazuo Fujimaki

Masashi Norimoto

Yuichi Kakizono

Tadashi Denda

Akihiro Kudo

A method for manufacturing an epitaxial wafer that can reduce occurrence of a surface defect or a slip formed on an epitaxial layer is provided. The manufacturing method is characterized by comprising: a smoothing step of controlling application of an etchant to a wafer surface in accordance with a surface shape of a silicon wafer to smooth the wafer surface; and an epitaxial layer forming step of forming an epitaxial layer formed of a silicon single crystal on the surface of the wafer based on epitaxial growth.

Method for manufacturing epitaxial wafer

An object of the present invention is to provide a method for etching a single wafer, which effectively realizes a high flatness of wafer and an increase in productivity thereof. In a method for etching a single wafer, a single thin disk-like wafer sliced from a silicon single crystal ingot is spun, and a front surface of the wafer is etched with an etching solution supplied thereto. In the method, a plurality of supply nozzles are disposed above and opposite to the front surface of the wafer at different portions in the radial direction of the wafer, respectively; and then one or more conditions selected from the group consisting of temperatures, kinds, and supply flow rates of etching solutions from the plurality of supply nozzles are changed.

Method for etching single wafer

An apparatus for etching a wafer by a single-wafer process comprises a fluid supplying device which feeds an etching fluid on a wafer, and a wafer-chuck for horizontally holding the wafer. The wafer-chuck is equipped with a gas injection device for injecting a gas to the wafer, a first fluid-aspirating device, and a second fluid-aspirating device. The etching fluid supplied on the wafer is spread by a rotation of the wafer. The etching fluid is scattered by a centrifugal force, or flows down over an edge portion of the wafer and is blown-off by the gas injected from the gas injection unit, and is aspirated by the first fluid-aspirating device or the second fluid-aspirating device.

Apparatus for etching wafer by single-wafer process and single wafer type method for etching wafer

Disclosed is a method for smoothing the surface of at least one side of a wafer which is obtained by slicing a semiconductor ingot. In this method, a fluid is applied according to projections of the wafer surface, thereby reducing the projections. Alternatively, a fluid is applied over the wafer surface, thereby smoothing the entire surface of the wafer while reducing the projections in the wafer surface.

Method for smoothing wafer surface and apparatus used therefor

An object of the present invention is to provide a single wafer etching apparatus realizing a high flatness of wafers and an increase in productivity thereof. In the single wafer etching apparatus, a single thin disk-like wafer sliced from a silicon single crystal ingot is mounted on a wafer chuck and spun thereon, and an overall front surface of the wafer is etched with an etching solution supplied thereto by centrifugal force generated by spinning the wafer. The singe wafer etching apparatus includes a plurality of supply nozzlescapable of discharging the etching solutionfrom discharge openingsonto the front surface of the wafer, nozzle-moving devices each capable of independently moving the plurality of supply nozzles, and an etching solution supplying devicefor supplying the etching solutionto each of the plurality of supply nozzles and discharging the etching solutionfrom each of the discharge openings to the front surface of the wafer

Single wafer etching method

An alkali etchant for controlling surface roughness of a semiconductor wafer, which is a sodium hydroxide solution or a potassium hydroxide solution having a weight concentration of 55 wt % to 70 wt %.

Alkaline etchant for controlling surface roughness of semiconductor wafer

This wafer polishing apparatus includes: a polishing plate having a polishing pad; a carrier plate which is placed facing the polishing pad and which slides and presses wafers against the polishing pad, while rotating in a state of holding the wafers; and an abrasive slurry supply device, wherein the abrasive slurry supply device is able to supply different abrasive slurries, each of the abrasive slurries contains abrasives of which the average grain size is different from those contained in the other abrasive slurries. This method for polishing wafers includes: while supplying an abrasive slurry to a surface of a polishing pad, sliding and pressing wafers against the polishing pad, wherein different abrasive slurries are supplied to the surface of the polishing pad, and each of the abrasive slurries contains abrasives of which the average grain size is different from those contained in the other abrasive slurries.

Wafer polishing apparatus and method for polishing wafers

A process for producing a silicon wafer comprising a single-wafer etching step of performing an etching by supplying an etching solution through a supplying-nozzle to a surface of a single and a thin-discal wafer obtained by slicing a silicon single crystal ingot and rotating the wafer to spread the etching solution over all the surface of the wafer; and a grinding step of grinding the surface of the wafer, in this order, wherein the etching solution used in the single-wafer etching step is an aqueous acid solution which contains hydrogen fluoride, nitric acid, and phosphoric acid in an amount such that the content of which by weight % at a mixing rate of fluoric acid:nitric acid:phosphoric acid is 0.5 to 40%:5 to 50%:5 to 70%, respectively.

Process for producing silicon wafer

The manufacturing method of the present invention provides a silicon wafer, both sides of the wafer having a highly accurate flatness and small surface roughness, which is a single surface mirror-polished wafer with the front and rear surfaces of the wafer identifiable by visual observation, and excellent in flatness when held by a stepper chuck and the like. The manufacturing method of the present invention includes an etching process, a lapping process, and a double surface polishing process to simultaneously polish the front and rear surfaces of a wafer after the etching process. The polishing removal depth (A) of the wafer front surface is 5 to 10 &#x3bc;m in the double surface simultaneous polishing process, and the polishing removal depth (B) in the rear surface is 2 to 6 &#x3bc;m, and a difference between the polishing removal depth A and the polishing removal depth B is 3 to 4 &#x3bc;m.

Manufacturing method of silicon wafer

This silicon wafer production process comprises in the order indicated a planarization step, in which the front surface and the rear surface of a wafer are ground or lapped, a single-wafer acid etching step, in which an acid etching liquid is supplied to the surface of the wafer while spinning and the entire wafer surface is etched to control the surface roughness Ra to 0.20 &#x3bc;m or less, and a double-sided simultaneous polishing step, in which the front surface and the rear surface of the acid etched wafer are polished simultaneously. The process may comprise a single-sided polishing step, in which the top and bottom of the acid etched wafer are polished in turn, instead of the double-sided simultaneously polishing step.

Method for manufacturing silicon wafers

The inventive method for processing a silicon wafer is a method comprising stepin which a single crystal ingot is sliced into thin disc-like wafers; stepin which the surface of each wafer is lapped to be planar; stepin which the wafer is subjected to alkaline cleaning to be removed of contaminants resulting from preceding machining; and stepin which the wafer is alternately transferred between two groups of etching tanks one of which contain acidic etching solutions and the other alkaline etching solutions, wherein an additional stepis introduced between stepand stepin which a wafer is immersed in an acidic solution containing hydrofluoric acid (HF) and nitric acid (HNO) at a volume ratio of &#x215b; to &#xbd; (HF/HNO) so that degraded superficial layers occurring on the front and rear surfaces of the wafer as a result of machining can be removed and the edge surface of the wafer can be beveled. The inventive method simplifies the steps involved in the processing of a wafer, and reduces the intervention of alkaline cleaning accompanied with mechanical beveling, thereby reducing the risk of contamination due to metal impurities which may result from alkaline cleaning.

Method of processing silicon wafer

Apparatus for etching wafer by single-wafer process

Provided is a method for producing a silicon wafer whose surfaces exhibit precise flatness and minute surface roughness, and which allows one to visually discriminate between the front and rear surfaces, the method comprising a slicing step of slicing a single-crystal ingot into thin disc-like wafers, a chamfering step of chamfering the wafer, a lapping step for flattening the chamfered wafer, a mild lapping step for abrading away part of processing distortions on the rear surface of the wafer left after chamfering and lapping, a rear-surface mild polishing step for abrading away part of roughness on the rear surface of the wafer, an etching step for alkali-etching the remains of processing distortions on the front and rear surfaces of the wafer, a front-surface mirror-polishing step for mirror-polishing the front surface of the etched wafer, and a cleaning step for cleaning the mirror-polished wafer.

Method for producing a silicon wafer

A surface of a semiconductor wafer which has been lapped is ground. This removes a damage caused on the wafer surface during lapping, thereby increasing the flatness of the wafer surface. Next, the wafer is subjected to composite etching and the both surfaces are polished, i.e., subjected to mirror polishing while the wafer rear surface is slightly polished so as to obtain a single-side mirror surface wafer having a difference between the front and the rear surfaces. As compared to mere acid etching or alkali etching, it is possible to manufacture a single-side mirror surface wafer having a higher flatness.

Method for manufacturing single-side mirror surface wafer

A method for manufacturing a silicon wafer includes a planarizing processfor polishing or lapping the upperside and lowerside surfaces of a thin disk-shaped silicon wafer obtained by slicing a silicon single crystal ingot, an etching process for dipping the silicon wafer into the etching liquid wherein silica powder is dispersed uniformly in an alkali aqueous solution, thereby etching the upperside and lowerside surfaces of the silicon wafer, and a both-side simultaneous polishing processfor polishing the upperside and lowerside surfaces of the etched silicon wafer simultaneously or a one-side polishing process for polishing the upperside and lowerside surfaces of the etched silicon wafer one after another, in this order.

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Tokyo, Japan

Sakae Koyata