Shin-Etsu Handotai Co., Ltd.

Daisuke Nakamata

Hiroshi Oishi

Hisakazu Takano

Keiichi Okabe

Atsuo Uchiyama

Yukio Hijirisawa

Hitoshi Sejimo

A method of resuming operation of a wire saw in which slicing of a workpiece is suspended due to a wire break, including processes of: imparting axial reciprocating motion to a wire while supplying a new line of the wire; and slicing the workpiece into wafers by moving the workpiece downwardly to press the workpiece against the reciprocating wire while supplying a slicing slurry to the wire, the method includes: repairing the broken wire after suspending the slicing of the workpiece before resuming the slicing of the workpiece; and preparing for the slicing in that a diameter of the repaired wire at a position at which the workpiece is to be sliced is matched to the diameter of the wire just before occurrence of the wire break. The method can inhibit the formation of grooves in wafers sliced after the resumption and reduce low-quality production wafers.

Method of resuming operation of wire saw

A wafer slicing method includes winding a wire around rollers and pressing the wire against an ingot while supplying slurry to the rollers. A previously conducted experiment provides a supply temperature profile of the slurry during the slicing process and the relationship to the axial displacement of the rollers. This relationship is used to implement slurry delivery during the slicing process. The resultant wafers are bowed in a uniform direction. This slicing method provides excellent reproducibility in addition to producing wafers that are bowed in a uniform direction.

Slicing method and method for manufacturing epitaxial wafer

The present invention provides a slicing method comprising winding a wire around a plurality of grooved rollers and pressing the wire against an ingot to be sliced into wafers while supplying a slurry for slicing to the grooved rollers and causing the wire to travel, wherein a supply temperature of the slurry for slicing is controlled, and slicing is performed in such a manner that the supply temperature of the slurry for slicing and a temperature of the ingot become at least 30&#xb0; C. or above at end of slicing the ingot. As a result, there is provided the slicing method that can alleviate precipitous cooling of an ingot in the time close to end of slicing the ingot and thereby suppress production of a nano-topography when slicing the ingot by using a wire saw.

Slicing method

The present invention provides a slicing method comprising winding a wire around a plurality of grooved rollers and pressing the wire against an ingot to be sliced into wafers while supplying a slurry for slicing to the grooved rollers and causing the wire to travel, wherein a cooling speed of the ingot when a slicing depth is equal to or above &#x2154; of a diameter is controlled to perform slicing by supplying a slurry for adjusting an ingot temperature to the ingot independently from the slurry for slicing while controlling a supply temperature only in a period from the moment that the slicing depth of the ingot reaches at least &#x2154; of the diameter to end of slicing. As a result, the slicing method is provided, in which rapid cooling of the ingot in the time close to end of slicing the ingot can be alleviated when a wire saw is used to slice the ingot, and generation of a nano-topography can be thereby suppressed and further high quality wafers having a uniform thickness are obtained by slicing.

The present invention provides a method for evaluating nanotopography of a surface of a semiconductor wafer sliced from a semiconductor ingot, the method being conducted prior to polishing of the surface, the method at least comprising: measuring a surface profile of the wafer in the direction that the wafer is sliced; determining a maximum inclination value of warp change of the wafer surface in a sectional profile in the direction that the wafer is sliced of the measured surface profile; and estimating nanotopography of the wafer surface after being polished based on the determined maximum value. As a result, there are provided a method and an apparatus for evaluating nanotopography of a surface of a semiconductor wafer, and a method for manufacturing a semiconductor wafer exhibiting good nanotopography level on the surface.

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Chikuma, Japan

Daisuke Nakamata