US 6,330,971 B1Granted

Radio frequency identification system and method for tracking silicon wafers

AssigneeMEMC Electronic Materials, Inc.

InventorsFrank Robert Mabry, James Scott Rhodes

Life of this patent

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Abstract

A system and method for tracking semiconductor wafers through processing operations performed at a plurality of stations. A reader reads information relating to and identifying the wafers from a tag mounted on a wafer carrier. The tag has a memory which includes a plurality of pages storing the information. A plurality of antennas are connected to the reader. The antennas each have a transmission range which defines a reader position and the reader and tag communicate by radio frequency signals via one of the antennas when the carrier is at the respective reader position. A host computer and reader communicate in accordance with an interface protocol by which the host computer commands the reader to read the stored information from one or more selected tag pages and the reader provides the stored information read from the selected tag pages to the host computer.

Claims20

Dependent claims

A system for tracking semiconductor wafers through processing operations performed in a predetermined sequence at a plurality of stations, said wafers being loaded in one or more wafer carriers for transport between the stations, said system comprising:

a passive tag mounted on the carrier, said tag including a memory which has a plurality of pages storing information identifying the carrier and information relating to the wafers in the carrier and the sequence of processing operations to be performed at the stations, said stored information including information identifying the carrier and the processing operations, said information identifying the carrier being stored in a selected one of said tag pages and including data representative of a carrier identification address, said carrier identification address being stored in the selected one of the tag pages storing the information identifying the carrier and being permanently write-locked, said remaining tag pages including at least one reserved page to which information from another one of the pages is transferred in the event that the other page fails;
a reader for reading the stored information from the tag pages;
a plurality of antennas connected to the reader, each antenna being located proximate to one or more of the stations and having a transmission range which defines a reader position, said reader and tag communicating by radio frequency signals via one of the antennas when the carrier is at the respective reader position;
and
a host computer for processing the stored information read by the reader to track the wafers, said host computer and reader communicating in accordance with an interface protocol by which the host computer commands the reader to read the stored information from one or more selected tag pages and the reader provides the stored information read from the selected tag pages to the host computer.

2 more elements

A method of tracking semiconductor wafers through processing operations performed in a predetermined sequence at a plurality of stations, said wafers being loaded in one or more wafer carriers for transport between the stations, said method comprising the steps of:

mounting a passive tag on the carrier, said tag including a memory which has a plurality of pages storing information identifying the carrier and information relating to the wafers in the carrier and the sequence of processing operations to be performed at the stations;
storing information in the memory of the tag identifying the carrier and the processing operations, said information identifying the carrier being stored in a selected one of said tag pages and including data representative of a carrier identification address, said carrier identification address being stored in the selected one of the tag pages storing the information identifying the carrier, said remaining tag pages including at least one reserved page;
permanently write-locking the selected tag page storing the information identifying the carrier;
connecting a plurality of antennas to a reader for reading the stored information from the tag pages;
locating each antenna proximate to one or more of the stations, each antenna having a transmission range which defines a reader position;
communicating between the tag and the reader by radio frequency signals via one of the antennas when the carrier is at the respective reader position;
interfacing a host computer with the reader in accordance with an interface protocol by which the host computer commands the reader to read the stored information from one or more selected tag pages and the reader provides the stored information read from the selected tag pages to the host computer;
processing the stored information read by the reader with a host computer to track the wafers;
and
transferring information to the reserved page from another one of the pages in the event that the other page fails.

7 more elements

A method of interfacing a radio frequency identification (RFID) system to a host computer, said RFID system including a tag having a memory which includes a plurality of pages for storing information and including a reader for reading information from the tag pages, said tag being mounted on a carrier for transporting semiconductor wafers between a plurality of stations in a predetermined sequence, said method comprising the steps of:

storing information identifying the carrier including data representative of a carrier identification address in a selected one of the tag pages, said remaining tag pages including at least one reserved page;
permanently write-locking the selected tag page storing the information identifying the carrier;
generating a radio frequency interrogation signal with the reader, said tag being responsive to the interrogation signal for initiating communication between the reader and the tag;
transmitting the interrogation signal with an antenna connected to the reader, said antenna having a transmission range which defines a reader position, said tag receiving the interrogation signal when the tag is at the reader position;
generating a radio frequency reply signal with the tag in response to the interrogation signal when the carrier is at the reader position;
and
interfacing the host computer with the reader in accordance with an interface protocol, said interfacing step being responsive to the reply signal and including communicating unsolicited data messages from the reader to the host computer and communicating query commands from the host computer to the reader in response to the unsolicited data messages, said commands causing the reader to read the information from one or more selected tag pages in response to the data messages and to provide the information read from the selected tag pages to the host computer, said information identifying the carrier and relating to the wafers in the carrier and the sequence of processing operations to be performed at the stations;
and
transferring information to the reserved page from another one of the pages in the event that the other page fails.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/677,909Filed 3 Oct 2000 · continuation
Priority: 7 Jul 1998
Granted: 18 Dec 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H10P 72/0618
Apparatus for monitoring, sorting, marking, testing or measuring: using identification means, e.g. labels on substrates or labels on containers
G03F 7/70541
Information management, e.g. software; Active and passive control, e.g. details of controlling exposure processes or exposure tool monitoring…:…
G03F 7/7075
Handling masks and workpieces, e.g. exchange of workpiece or mask, transport of workpiece or mask: handling workpieces outside exposure position,…
H10P 72/0612
Apparatus for monitoring, sorting, marking, testing or measuring: production flow monitoring, e.g. for increasing throughput