# US 5,702,522 A · Method of operating a growing hall containing puller cells

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- Number: US 5,702,522 A
- Document ID: US5702522A
- Status: Granted
- Kind: A
- Application number: 08/706,502
- Filed: 1996-09-05
- Granted: 1997-12-30
- Earliest claimed: 1995-07-10
- Assignees: SEH America, Inc.
- Inventors: Kazuo Sakauchi; Yoshihiro Hirano; Akira Uchikawa
- Web page: https://patentgrep.com/patent/US5702522A

## CPC

- F24F 3/167: Clean rooms, i.e. enclosed spaces in which a uniform flow of filtered air is distributed (air distribution by perforated walls F24F7/10)
- C30B 15/00: Single-crystal growth by pulling from a melt, e.g. Czochralski method (under a protective fluid C30B27/00)
- F24F 3/163: Clean air work stations, i.e. selected areas within a space which filtered air is passed
- F24F 11/77: by controlling the speed of ventilators
- Y02B 30/70: Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
- Y10S 117/90: Apparatus characterized by composition or treatment thereof, e.g. surface finish, surface coating
- Y10T 117/10: Apparatus
- Y10T 117/1004: with means for measuring, testing, or sensing
- F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02)
- 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
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A crystal puller cell (18) provides a low particulate environment for an individual crystal puller (28). The airflow within each cell is adjustable so that a particulate level appropriate to the activity within the cell is maintained, thereby avoiding the cost of maintaining an entire growing hall (10) at a constant high level of cleanliness. Each cell includes a multi-level floor (46) that includes an operator floor (48) and a maintenance floor (52). A door (62) at the maintenance floor level opens onto a maintenance aisle used to service the machines. A door (64), at the operator floor level, opens onto a clean aisle for transporting raw material and finished product. The cell walls can include magnetic shielding if a magnetic growing process is used to reduce exposure of operators and other machines to intense magnetic fields.

## Claims

### Claim 1

A method of operating a growing hall to reduce clean room costs and improve cleanliness, comprising:
dividing the growing hall with walls into at least one of a clean aisle, one of a maintenance aisle, and one of a crystal puller cell;
maintaining a different airborne particulate level in the clean aisle, maintenance aisle, and the crystal puller cell respectively.

### Claim 2 (depends on 1)

The method of claim 1 further comprising:
maintaining a first airborne particulate level in the maintenance aisle;
maintaining a second airborne particulate level in the clean aisle, the second airborne particulate level being lower than the first airborne particulate level; and
maintaining a third airborne particulate level in the crystal puller cell, the third airborne particulate level being selected from at least two possible levels, the selection being based upon the activities within the crystal puller cell.

### Claim 3 (depends on 2)

The method of claim 2 in which each crystal puller cell has a door that opens onto the maintenance aisle and a door that opens onto the clean aisle and in which maintaining the third airborne particulate level includes selectively prohibiting air transfer between the crystal puller cell and the clean and maintenance aisles, the selective prohibition of air transfer being accomplished by precluding the opening of the door between the crystal puller cell and the respective clean and maintenance aisles when the third particulate level is not compatible with the respective first and second particulate levels.

### Claim 4 (depends on 2)

The method of claim 2 in which each crystal puller cell has a door that opens onto the maintenance aisle and a door that opens onto the clean aisle and in which maintaining the first and second airborne particulate levels includes prohibiting the clean and maintenance aisle by precluding the simultaneous opening of both doors to crystal puller cell.