Shared sensors for detecting substrate position/presence

An apparatus for detecting substrates, comprising:

• a transfer chamber adapted to couple to at least one processing chamber and at least one load lock chamber;
• a first ring of sensors disposed within the transfer chamber at a first radius from a center of the transfer chamber;
• and
• a second ring of sensors disposed within the transfer chamber at a second radius from the center of the transfer chamber;
• wherein the sensors are positioned and the first radius and the second radius are selected so that a position of a four-sided substrate may be detected in front of an opening of each processing chamber and load lock chamber coupled to the transfer chamber without requiring four separate sensors for each processing chamber and load lock chamber coupled to the transfer chamber.

A method of detecting substrates comprising:

• positioning a first group of sensors in a transfer chamber to indicate that a substrate is disposed for loading into a first chamber coupled to the transfer chamber;
• and
• positioning a second group of sensors in the transfer chamber to indicate that a substrate is disposed for loading into a second chamber coupled to the transfer chamber;
• wherein:
• the first chamber is not adjacent the second chamber;
• and
• at least one sensor of the first group of sensors also belongs to the second group of sensors.

A method of detecting substrates, comprising:

• disposing a first ring of sensors within a transfer chamber at a first radius from a center of the transfer chamber;
• and
• disposing a second ring of sensors within the transfer chamber at a second radius from the center of the transfer chamber;
• wherein the sensors are positioned and the first radius and the second radius are selected so that a position of a four-sided substrate may be detected in front of an opening of each chamber coupled to the transfer chamber without requiring four separate sensors for each chamber coupled to the transfer chamber.

An apparatus for detecting substrates comprising:

• a transfer chamber adapted to couple to seven other chambers, including a first chamber, a second chamber, a third chamber, a fourth chamber, a fifth chamber, a sixth chamber and a seventh chamber;
• and
• fourteen sensors disposed in the transfer chamber, including a first sensor, a second sensor, a third sensor, a fourth sensor, a fifth sensor, a sixth sensor, a seventh sensor, an eighth sensor, a ninth sensor, a tenth sensor, an eleventh sensor, a twelfth sensor, a thirteenth sensor and a fourteenth sensor;
• wherein:
• the first, second, tenth and thirteenth sensors are positioned to detect whether a substrate is disposed for loading into the first chamber;
• the second, third, eleventh and fourteenth sensors are positioned to detect whether a substrate is disposed for loading into the second chamber;
• the third, fourth, eighth and twelfth sensors are positioned to detect whether a substrate is disposed for loading into the third chamber;
• the fourth, fifth, ninth and thirteenth sensors are positioned to detect whether a substrate is disposed for loading into the fourth chamber;
• the fifth, sixth, tenth and fourteenth sensors are positioned to detect whether a substrate is disposed for loading into the fifth chamber;
• the sixth, seventh, eighth and eleventh sensors are positioned to detect whether a substrate is disposed for loading into the sixth chamber;
• and
• the first, seventh, ninth and twelfth sensors are positioned to detect whether a substrate is disposed for loading into the seventh chamber.

A method of detecting substrates, comprising:

• using a first sensor, a second sensor, a tenth sensor and a thirteenth sensor to detect whether a substrate is disposed for loading into a first chamber;
• using the second sensor, a third sensor, an eleventh sensor and a fourteenth sensor to detect whether a substrate is disposed for loading into a second chamber;
• using the third sensor, a fourth sensor, an eighth sensor and a twelfth sensor to detect whether a substrate is disposed for loading into a third chamber;
• using the fourth sensor, a fifth sensor, a ninth sensor and the thirteenth sensor to detect whether a substrate is disposed for loading into a fourth chamber;
• using the fifth sensor, a sixth sensor, the tenth sensor and the fourteenth sensor to detect whether a substrate is disposed for loading into a fifth chamber;
• using the sixth sensor, a seventh sensor, the eighth sensor and the eleventh sensor to detect whether a substrate is disposed for loading into a sixth chamber;
• and
• using the first sensor, the seventh sensor, the ninth sensor and the twelfth sensor to detect whether a substrate is disposed for loading into a seventh chamber.