Slicing method and method for manufacturing epitaxial wafer
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.
1. A slicing method comprising:
winding a wire around a plurality of grooved rollers,
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 test of slicing the ingot while supplying the slurry to the grooved rollers and controlling a supply temperature thereof is previously conducted to examine a relationship between an axial displacement of the grooved rollers and a supply temperature of the slurry,
a supply temperature profile of the slurry is set based on the relationship between an axial displacement of the grooved rollers and a supply temperature of the slurry, and
the slurry is supplied based on the supply temperature profile such that the ingot is sliced while controlling an axial displacement of the grooved rollers, and the resultant wafers of the ingot are bowed in a uniform direction.
2. The slicing method according to claim 1 , wherein the supply temperature profile of the slurry is adjusted to adjust amounts of bow of all the wafers to be sliced.
3. The slicing method according to claim 1 , wherein the supply temperature profile of the slurry is set such that the supply temperature is gradually increased after a slicing depth of the ingot reaches at least ½of a diameter.
4. The slicing method according to claim 2 , wherein the supply temperature profile of the slurry is set such that the supply temperature is gradually increased after a slicing depth of the ingot reaches at least ½of a diameter.
5. The slicing method according to claim 1 , wherein the supply temperature profile of the slurry is set such that the supply temperature is gradually increased from start of slicing the ingot.
6. The slicing method according to claim 2 , wherein the supply temperature profile of the slurry is set such that the supply temperature is gradually increased from start of slicing the ingot.
7. A method for manufacturing an epitaxial wafer, wherein wafers that bow uniformly in one direction are sliced out by the slicing method according to claim 1 , and an epitaxial layer is deposited on the wafers that bow uniformly in one direction.
8. A method for manufacturing an epitaxial wafer, wherein wafers that bow uniformly in one direction are sliced out by the slicing method according to claim 2 , and an epitaxial layer is deposited on the wafers that bow uniformly in one direction.
9. A method for manufacturing an epitaxial wafer, wherein wafers that bow uniformly in one direction are sliced out by the slicing method according to claim 3 , and an epitaxial layer is deposited on the wafers that bow uniformly in one direction.
10. A method for manufacturing an epitaxial wafer, wherein wafers that bow uniformly in one direction are sliced out by the slicing method according to claim 4 , and an epitaxial layer is deposited on the wafers that bow uniformly in one direction.
11. A method for manufacturing an epitaxial wafer, wherein wafers that bow uniformly in one direction are sliced out by the slicing method according to claim 5 , and an epitaxial layer is deposited on the wafers that bow uniformly in one direction.
12. A method for manufacturing an epitaxial wafer, wherein wafers that bow uniformly in one direction are sliced out by the slicing method according to claim 6 , and an epitaxial layer is deposited on the wafers that bow uniformly in one direction.