THE BROOKHAVEN INSTRUMENTS CORPORATION LENSMASTER
The Brookhaven Instruments Corporation’s Lensmaster is a plug-compatible high-voltage power supply for use on various models of Varian’s medium-current ion implanters. The Lensmaster has supervisory circuits not to be found in the original equipment as supplied with the implanter. These new circuits provide protection against the loss of wafers during production. New high-voltage leads, from the Lensmaster to the lens’ feed-throughs, are provided with the unit. The output voltages are 0 to 10 kV (two positive and two negative) and they track with energy. The ‘A’ voltages and the ‘B’ voltages increase or decrease appropriately with the adjustment of the ‘Balance’ potentiometer.
One major advantage of the Brookhaven Lensmaster is the inclusion of a fault detector board, similar to that of the Scanmaster. The supervisory circuits detect if any one of the four outputs becomes missing. When the (fault) condition is detected, an alarm sounds, the appropriate LED illuminates, and the machine is placed in a hold condition. Other new circuits also detect a difference between the absolute values of the A+ and A- (also B+ and B-), and if the difference is 10% or more, the fault detector board will sound an alarm, flash the appropriate pair of LEDs and stop the process.
Another advantage of the Lensmaster is an active load for the positive supplies. If the beam hits the lens, the supply will sink the current as opposed to the output going up in voltage or just exploding. The positive supplies can sink 4 mA of beam current. A third advantage is 4 LCD meters mounted on the front panel giving a direct indication of the output voltages (output divided by 1000). The Lensmaster installs in the place of the old scanner DC supply, so a machine with the vacuum tube amplifiers would have to accept the unit mounted on top or some other place (this place on a machine with a scanmaster is likely not utilized).
A third connector on the rear panel brings the divided-down outputs out so that a customer with a PCT-type system could monitor and interlock the lens supply if so desired. A Lensmaster was tested on a 300XP ion implanter on Sept 28, 2004 at a fab in north Texas. It performed very well from low energy to high energy. Their test wafer indicated sheet resistance was normal.
Specifications --- Lensmaster
Brookhaven P/N: 35520460
Input Voltage: 0 to +10 VDC as per original equipment.
Connectors: 7-pin Hex connectors and a 14 pin
Outputs: Four individual outputs, 0 to 10 KVDC. The A+ and B+ outputs are positive and the A- and B- outputs are negative. The outputs track with machine energy.
Output Monitoring: Individual LCD displays (4), on the front panel, display output voltages. A connector on the rear panel of the instruments allows for remote monitoring. All output-monitoring signals represent the output voltage divided by 1000.
Fault Detection: Typical time from the occurrence of a fault until implantation is stopped is 20 mSec. Types of faults monitored are missing output voltages and A+ not equal to A- and B+ not equal to B-.
Dimensions: Standard 19” rack mount, 10.5” tall, and 15.3” deep.
Weight: 26 pounds.
Mounting: The unit will be located in the place of the old scanner power supply, immediately below the location of the existing lens power supply.
Power Requirements: 120 VAC ± 10%, 50/60 Hz.