# US 2021/0340690 A1 · Device for pulling a single crystal of semiconductor material out of a melt using the cz method, and method using the device

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- Number: US 2021/0340690 A1
- Document ID: US20210340690A1
- Status: Published application
- Kind: A1
- Application number: 17/279,623
- Filed: 2019-09-27
- Published: 2021-11-04
- Earliest claimed: 2018-10-12
- Assignees: Siltronic AG
- Applicants: Siltronic AG
- Inventors: Alexander Molchanov
- Web page: https://patentgrep.com/patent/US20210340690A1

## CPC

- C30B 15/14: Heating of the melt or the crystallised materials
- C30B 15/26: using television detectors; using photo or X-ray detectors
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR

## Abstract

An apparatus pulls a single crystal of semiconductor material by the Czochralski (CZ) method from a melt. The apparatus includes: a crucible that accommodates the melt; a resistance heater around the crucible; a camera system for observing a phase boundary between the melt and a growing single crystal, the camera system having an optical axis; a heat shield in frustoconical form with a narrowing diameter in a region at its lower end and arranged above the crucible and surrounding the growing single crystal; and an annular element, which is configured to capture particles, that projects inward from an inner side face of the heat shield and has an arrestor edge directed upward at an inner end of the annular element. The optical axis of the camera system runs between the arrestor edge and the growing single crystal. The annular element is releasably connected to the heat shield.

## Claims

### Claim 1

An apparatus for pulling a single crystal of semiconductor material by the Czochralski (CZ) method from a melt, the apparatus comprising:
a crucible configured to accommodate the melt;
a resistance heater arranged around the crucible;
a camera system for observing a phase boundary between the melt and a growing single crystal, where the camera system has an optical axis;
a heat shield in frustoconical form with a narrowing diameter in a region of a lower end of the heat shield and arranged above the crucible and surrounding the growing single crystal; and
an annular element, which is configured to capture particles, that projects inward from an inner side face of the heat shield and has an arrestor edge directed upward at an inner end of the annular element,
wherein the optical axis of the camera system runs between the arrestor edge and the growing single crystal, and
wherein the annular element is releasably connected to the heat shield.

### Claim 2 (depends on 1)

The device as claimed in claim 1, wherein the annular element is at a distance from the lower end of the heat shield.

### Claim 3 (depends on 2)

The device as claimed in claim 2, wherein the distance is 10 mm to 100 mm.

### Claim 4 (depends on 1)

The device as claimed in claim 1, wherein the arrestor edge is in an inclined arrangement relative to the heat shield.

### Claim 5 (depends on 1)

A method of pulling a single crystal of semiconductor material in an apparatus as claimed in claim 1, the method comprising:
charging the crucible with solid semiconductor material;
melting a portion or an entire mass of the solid semiconductor material;
further charging the crucible with further solid semiconductor material;
heating the crucible contents until the crucible contents have melted completely; and
pulling the single crystal by the CZ method.