Epitaxial substrate for solid-state imaging device with gettering sink, semiconductor device, back illuminated solid-state imaging device and manufacturing method thereof
AssigneeSumco Corporation
InventorKazunari Kurita
Life of this patent
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Abstract
A semiconductor wafer is set in a laser irradiation apparatus, and laser beam irradiation is performed while the semiconductor wafer is moved. At this time, a laser beam emitted from a laser generating apparatus is condensed by a condensing lens so that the condensing point (focal point) is positioned at a depth of several tens of gm or so from one surface of the semiconductor wafer. Thereby, the crystal structure of the semiconductor wafer in the position having such a depth is modified, and a gettering sink is formed.
Claims33
A method of manufacturing an epitaxial substrate for a solid-state imaging device, comprising the steps of:
- growing an epitaxial layer on one surface of a semiconductor substrate to form an epitaxial substrate;
- forming a gettering sink in which a crystal structure of an arbitrary microscopic region of the semiconductor substrate is changed, by causing a laser beam to be incident on the epitaxial substrate through a condensing means and condensing the laser beam in the microscopic region, to cause a multi-photon absorption process to occur in the microscopic region;
- and
- annealing the epitaxial substrate at a predetermined temperature to capture heavy metals in the gettering sink.
A method of manufacturing a semiconductor device, comprising at least the steps of:
- forming an insulating film on one surface of the semiconductor substrate;
- forming a gettering sink in which a crystal structure of an arbitrary microscopic region of the semiconductor substrate is changed, by causing a laser beam to be incident from the other surface of the semiconductor substrate through a condensing means and condensing the laser beam in the microscopic region, to cause a multi-photon absorption process to occur in the microscopic region;
- and
- annealing the semiconductor substrate at a predetermined temperature to capture heavy metals in the gettering sink.
A method of manufacturing a back illuminated solid-state imaging device, comprising at least the steps of:
- growing an epitaxial layer on one surface of a semiconductor substrate to form an epitaxial substrate;
- forming a gettering sink in which a crystal structure of an arbitrary microscopic region of the semiconductor substrate is changed, by causing a laser beam to be incident to the epitaxial substrate through a condensing means and condensing the laser beam in the microscopic region, to cause a multi-photon absorption process to occur in the microscopic region;
- forming a plurality of photodiodes in the epitaxial substrate;
- annealing the epitaxial substrate at a predetermined temperature to capture heavy metals in the gettering sink;
- and
- removing a region including the gettering sink by reducing the thickness of the semiconductor substrate.
An epitaxial substrate for a solid-state imaging device, comprising a semiconductor substrate;
- an epitaxial layer formed on one surface of the semiconductor substrate;
- a gettering sink formed by changing a crystal structure of an arbitrary microscopic region of the semiconductor substrate, by causing a laser beam to be incident on the semiconductor substrate through a condensing means and condensing the laser beam in the microscopic region, to cause a multi-photon absorption process to occur in the microscopic region;
- and a buried oxide film having a SOI structure formed between the gettering sink and the epitaxial layer.
A method of manufacturing a silicon wafer, comprising at least:
- a slicing step of slicing a silicon single crystal ingot to obtain a silicon wafer;
- a multi-photon absorbing step of forming a gettering sink in which a crystal structure of an arbitrary microscopic region is changed, by causing a laser beam to be incident on the silicon wafer through a condensing means and condensing the laser beam in the microscopic region, to cause a multi-photon absorption process to occur in the microscopic region;
- and
- a polishing step of mirror-polishing the silicon wafer through the multi-photon absorbing step.
Dependencies are inferred from the claim text.