Shin-Etsu Handotai Co., Ltd.

Pre-Tech Co., Ltd.

Shin.sub.-- Etsu Handotai Co., Ltd.

Shigeyoshi Netsu

Yasuyuki Harada

Makoto Tsukada

Kihachiro Watanabe

Kazuhiko Shiba

Shouichi Miura

Bee Chin Lim

Hiroshi Amano

Yee Ping Yap

Masaki Kameya

There is disclosed a silicon wafer etching method in which etching is performed through use of an etchant. The etchant is an alkali aqueous solution which contains an alkali component in a concentration ranging from 50.6% to 55.0% by weight. The alkali component is preferably sodium hydroxide. The silicon wafer etching method can reduce not only surface roughness but also dispersion thereof.

Silicon wafer etching method and silicon wafer etchant

In a cleaning apparatus, a cleaning solution spray means itself is given a function of producing OH.sup.- ionized water and H.sup.+ ionized water and can spray OH.sup.- ionized water and H.sup.+ ionized water, as cleaning solutions immediately after they are produced, upon a substrate to be cleaned, and one of OH.sup.- ionized water and H.sup.+ ionized water can be selectively used as a cleaning solution. This cleaning apparatus includes a substrate holding member for holding a substrate to be cleaned, and a cleaning solution spray member for spraying a cleaning solution upon the substrate. The cleaning solution spray member includes an electrolytic ion generating member for radical-activating or ionizing pure water, and an ultrasonic wave generating member for spraying the radical-activated or ionized pure water, by carrying it on ultrasonic waves, upon the substrate.

Cleaning apparatus and a cleaning method

An improvement is proposed in the cleaning treatment of semiconductor silicon wafers in which the conventional step of cleaning with an aqueous solution of an acid is replaced with a cleaning treatment with a temporarily acidic pure water which is produced electrolytically by the application of a DC voltage between an anode and a cathode bonded to the surfaces of a hydrogen-ion exchange membrane so that the acidic cleaning treatment can be performed under mild conditions so as to eliminate the troubles unavoidable in the conventional process. The apparatus used therefor comprises a rectangular vessel partitioned into a central anode compartment, in which the wafers are held in a vertical disposition within an upflow of pure water, and a pair of cathode compartments on both sides of the anode compartment by partitioning with a pair of hydrogen-ion exchange membranes, on both sides of which an anode plate and a cathode plate are bonded.

Apparatus and method for cleaning semiconductor wafers

An improvement is proposed in the cleaning treatment of semiconductor silicon wafers in which the conventional step of cleaning with an aqueous solution of an alkali is replaced with a cleaning treatment with a temporarily alkaline pure water which is produced electrolytically by the application of a DC voltage between a cathode and an anode bonded to the surfaces of a hydrogen-ion exchange membrane so that the alkaline cleaning treatment can be performed under mild conditions so as to eliminate the troubles due to formation of COPs unavoidable in the conventional process. In addition, the pure water rinse following the alkali cleaning of the wafers before transfer to the succeeding acidic cleaning step can be omitted to greatly contribute to the improvement of productivity. The apparatus used therefor comprises a rectangular vessel divided into a central cathode compartment, in which the wafers are held in a vertical disposition within an up-flow of pure water, and a pair of anode compartments by partitioning with a pair of hydrogen-ion exchange membranes, on both sides of which a cathode plate and anode plate are bonded.

An elastic foamed sheet is disclosed which is usable as waxless polishing backing pads for wafers and capable of producing mirror polish wafers excelling in flatness. This elastic foamed sheet possesses at least a foamed layer 2 and is characterized by the fact that a plurality of bubbles 4 in the foamed layer 2 meet the following conditions: (1) that the bubbles are slender discrete bubbles erected parallelly to one another and dispersed at a substantially equal pitch in the direction of width of the foamed layer 2 and the bubbles 4 are substantially equal in size, shape, and position of formation in the direction of thickness of the foamed layer 2, (2) that center lines of the bubbles 4 in the direction of length thereof are parallel to the direction of thickness of the foamed layer 2, and (3) that the diameters of the bubbles 4 are minimized in the terminal part of the foamed layer 2 on one surface side thereof and gradually increased in the direction from the one surface side to the other surface side of foamed layer 2 until the bubbles form openings 6 thereof in the surface of the foamed layer 2.

Elastic foamed sheet and wafer-polishing jig using the sheet

An elastic foamed sheet is disclosed which is usable as waxless polishing backing pads for wafers and capable of producing mirror polish wafers excelling in flatness. This elastic foamed sheet possesses at least a foamed layer 2 and is characterized by the fact that a plurality of bubbles 4 in the foamed layer 2 meet the following conditions:

Device for cleaning silicon wafers having an upper mist-generating chamber with a high frequency oscillator to generate an aqueous hydrofluoric acid mist and a lower region processing chamber separated by a partitioning wall having a shutter to open and close. Silicon wafers are held in an upright position in a rack. The processing chamber and the shutter have gas jets to eject gas between the silicon wafers and water spray heads in the processing chamber to spray water between the silicon wafers.

Growing community of inventors

Kuala Lumpur, Malaysia

Shigeyoshi Netsu