摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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 μm/sec to 0.05 μm/sec in total of the obverse and the reverse of the silicon wafer.
摘要:
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.
摘要:
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.
摘要:
It is possible to reduce workloads of a both-side simultaneous polishing process or a single-side polishing process, and to achieve both of the maintenance of the wafer flatness and the reduction in wafer front side roughness upon completing a flattening process. A method for manufacturing silicon wafers according to the present invention includes a flattening process 13 of grinding or lapping front and back sides of a thin disc-shaped silicon wafer obtained by slicing a silicon single crystal ingot, an etching process of immersing the silicon wafer in an etchant for controlling a silicon wafer surface shape in which a fluorochemical surfactant is uniformly mixed in an alkaline aqueous solution to etch the front and back sides of the silicon wafer, and a both-side simultaneous polishing process 16 of simultaneously polishing the front and back sides of the etched silicon wafer or a single-side polishing process of polishing the front and back sides of the etched wafer for every side, in this order.
摘要:
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.
摘要:
The manufacturing method of a silicon wafer of the present invention includes an etching process (14) storing acid etching solution and alkali etching solution in plural etching tanks, respectively, and immersing a silicon wafer gone through a lapping process and having degraded superficial layers in the acid etching solution and the alkali etching solution in order so as to remove the degraded superficial layers; and a double surface polishing process (16) to simultaneously polish the front and rear surfaces of the wafer after the etching process; wherein sodium hydroxide aqueous solution of 40 to 60 percent by weight is used in the alkali etching solution of the etching process, and the polishing removal depth A in the wafer front surface is made 5 to 10 μm in the double surface simultaneous polishing process, and the polishing removal depth B in the rear surface is made 2 to 6 μm, and a difference (A-B) between the polishing removal depth A and the polishing removal depth B is made 3 to 4 μm. The manufacturing method of the present invention provides a silicon wafer, in which both sides of the wafer have a highly accurate flatness and small surface roughness, and moreover, 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.