Abstract: 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.

Abstract: An apparatus for polishing wafers and a process for polishing wafers are provided. The apparatus for polishing a wafer which polishes the wafer W held by a carrier plate which rotates around an axis, by pressing and rubbing the wafer to a polishing pad disposed to a polishing platen 12 which rotates around another axis which differs from said axis, in which the polishing pad 11 is equipped with plural areas including a first area 11a and a second area 11b having hardness different from each other, each of the first 11a area and second area 11b being formed at a distribution and/or an area ratio such that the rate of the time or distance that the wafer W passes through the first area 11a during polishing to the time or distance that the wafer W passes through the second area 11b during polishing becomes a predetermined value.

Abstract: 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.

Abstract: The inventive method for processing a silicon wafer is a method comprising step 11 in which a single crystal ingot is sliced into thin disc-like wafers; step 13 in which the surface of each wafer is lapped to be planar; step 14 in which the wafer is subjected to alkaline cleaning to be removed of contaminants resulting from preceding machining; and step 16 in 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 step 12 is introduced between step 11 and step 13 in which a wafer is immersed in an acidic solution containing hydrofluoric acid (HF) and nitric acid (HNO3) at a volume ratio of ? to ½ (HF/HNO3) 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.

Abstract: The invention is improvement of a silicon wafer etching method of storing an acid etching solution and an alkali etching solution respectively in plural etching tanks, and immersing a silicon wafer having a work-degenerated layer, which has experienced a lapping process and then a cleaning process, in the acid etching solution and the alkali etching solution in order. Its characteristic configuration is in that an alkali etching process is performed after an acid etching process, the etching removal depth for acid etching is made to be equal to or larger than the etching removal depth for alkali etching, and the etching rate of acid etching is made to be 0.0075 ?m/sec to 0.05 ?m/sec in total of the obverse and the reverse of the silicon wafer.

Abstract: Provided is a method for producing a silicon wafer those 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 mirror-polishing step for mirror-polishing the surface of the etched wafer, and a cleaning step for cleaning the mirror-polished wafer.

Abstract: Provided is an improved 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 wafer, an etching step for removing processing distortions on the wafer surfaces, a mirror-polishing step for mirror-polishing the surface of the wafer, and a cleaning step for cleaning the wafer. The etching step further comprises a first acid-etching phase and a second alkali-etching phase, and a rear surface mild polishing step is introduced between the first and second etching phases in order to abrade part of roughness formed on the rear surface of the wafer as a result of the first etching phase.

Abstract: Disclosed is a washing solution of a semiconductor substrate which comprises 0.0001 to 0.1% by weight of an organic acid and 0.005 to 0.25 % by weight of hydrofluoric acid and has pH of 2 to 4. When a contaminated substrate is immersed in a washing solution, a naturally oxidized film on the surface of the substrate is removed by hydrofluoric acid, and fine particles on the film, metal impurities and metal impurities in the film transfer to the liquid. Since the washing solution is an acidic solution containing an organic acid and having pH of 2 to 4, fine particles are charged to minus as those of the fine particles, and the metal impurities ions in the liquid becomes minus complex ions due to complexing effect of the organic acid. As the results, surface potentials of the respective fine particles and metal impurities are each minus which is the same as that of surface potential of the substrate so that adhesion or re-adhesion to the substrate can be prevented.

Abstract: A method of treating a semiconductor substrate by first oxidizing and reducing the semiconductor substrate by immersion in an aqueous solution of ammonium hydroxide and hydrogen peroxide, and then oxidizing the semiconductor substrate by immersion in an aqueous solution of ozone, nitric acid, hydrogen peroxide, or mixtures thereof, and then reducing the oxidized semiconductor substrate by immersing it in a first aqueous solution composed of a mixture of hydrofluoric acid and an organic acid or salt thereof, thereafter rinsing the reduced semiconductor substrate by immersion in a second aqueous solution composed of a mixture of hydrofluoric acid and an organic acid or salt thereof, and then reoxidizing the rinsed semiconductor substrate by immersing it in an aqueous solution of ozone, nitric acid, hydrogen peroxide or mixtures thereof.

Abstract: A target unit includes a backing plate and a target member disposed on the backing plate. The target member includes at least one erosion member of a sputtering material and at least one holding member for releasably holding the erosion member on the backing plate.