Mono-crystalline silicon growth method
AssigneeGlobalWafers Co., Ltd.
InventorsChun-Hung Chen, Hsing-Pang Wang, Wen-Ching Hsu, I-Ching Li
Life of this patent
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Abstract
A mono-crystalline silicon growth method includes: providing a furnace, a supporting base and a crucible which do not rotate relative to the furnace, and a heating module disposed at an outer periphery of the supporting base. After solidifying a liquid surface of a silicon melt in the crucible to form a crystal, the heating power of the heating module is successively reduced to appropriately adjust the temperature around the crucible to effectively control a temperature gradient of a thermal field around the crucible, so as to form a mono-crystalline silicon ingot by solidifying the silicon melt.
Claims5
A mono-crystalline silicon growth method, comprising:
- a preparation step implemented by disposing a silicon melt in a crucible;
- an initiation step implemented by solidifying a liquid surface of the silicon melt to form a crystal and horizontally growing the crystal toward a side wall of the crucible to increase an outer diameter of the crystal;
- a shoulder-forming step implemented by adjusting a thermal field around the crucible when the outer diameter of the crystal reaches at least 90% of a predetermined value so that the outer diameter of the crystal reaches the predetermined value and the crystal is defined as a head crystal, and vertically growing the head crystal toward an inner bottom surface of the crucible;
- a body-forming step implemented by reducing a total heat output of a heating module so that the head crystal continuously crystallizes to form a first stage crystal, continuously reducing the total heat output of the heating module so that the first stage crystal continuously crystallizes to form a second stage crystal, and reducing the total heat output of the heating module again so that the second stage crystal continuously crystallizes to form a third stage crystal;
- and
- a tail-forming step implemented by reducing the total heat output of the heating module so that the third stage crystal continuously crystallizes to form a tail crystal, and detaching the tail crystal from the crucible to form a mono-crystalline silicon ingot by solidifying the silicon melt,
- wherein the total heat output of the heating module when forming the first stage crystal is from 93% to 97% of the total heat output of the heating module in the shoulder-forming step, the total heat output of the heating module when forming the tail crystal is from 93% to 97% of the total heat output of the heating module when forming the third stage crystal, the total heat output of the heating module when forming the second stage crystal is from 93% to 97% of the total heat output of the heating module when forming the first stage crystal, and the total heat output of the heating module when forming the third stage crystal is from 93% to 97% of the total heat output of the heating module when forming the second stage crystal, and
- wherein each of a volume of the first stage crystal, a volume of the second stage crystal, and a volume of the third stage crystal is from 23% to 32% of a volume of the mono-crystalline silicon ingot.
Dependencies are inferred from the claim text.