Vacuum Assembly Voltage Isolation Ion Implanter
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Solution Overview
Problem
Conventional ion implanters require turbomolecular pumps and backing pumps to be maintained at high voltage potentials, leading to the need for bulky motors, high operational costs, and potential vibration issues due to the requirement of three-phase AC power in the high voltage region, which affects the accuracy and reliability of the ion implantation process.
Innovation Solution
A vacuum assembly with a voltage isolator allows the backing pump to operate from three-phase AC power in physical and electrical isolation from turbomolecular pumps at or near ground potential, using a first turbomolecular pump at high voltage and a second turbomolecular pump at ground voltage to maintain vacuum conditions, thereby eliminating the need for three-phase AC power in the high voltage region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If backing pump is placed at high voltage potential to operate with turbomolecular pump, then vacuum conditions are maintained, but motor size increases and operational cost increases
Solution Approach 1:
The system is divided into two separate vacuum pumping systems: a high-voltage system with a first turbomolecular pump operating at high voltage potential, and a low-voltage system with a second turbomolecular pump and backing pump operating at ground potential. This segmentation allows the backing pump to use standard three-phase AC power without requiring high voltage isolation transformers, thereby reducing motor size and operational costs while maintaining vacuum conditions through the coordinated operation of both systems.
Solution Approach 2:
A voltage isolator serves as an intermediary component that electrically connects the high-voltage turbomolecular pump exhaust to the low-voltage backing pump. This isolator allows the exhaust from the high-voltage pump to be conducted to the backing pump without requiring the backing pump itself to operate at high voltage, thus enabling the use of standard power supplies and reducing motor size.
2Reliability
If backing pump operates at high voltage potential, then vacuum conditions are maintained, but operational cost increases
Solution Approach 1:
The vacuum system is segmented into high-voltage and low-voltage operational zones. The backing pump operates in the low-voltage zone using standard three-phase AC power, eliminating the need for expensive high-voltage isolation transformers and associated energy losses. This segmentation reduces operational costs while maintaining effective vacuum pumping through the coordinated operation of both high-voltage and low-voltage pumps.
Solution Approach 2:
The voltage isolator acts as an intermediary that enables the backing pump to operate at ground potential while still handling exhaust from the high-voltage turbomolecular pump. This eliminates the need for the backing pump to operate at high voltage, thereby reducing operational costs associated with high-voltage power conversion and isolation equipment.
3Productivity
If three-phase AC power is used in high voltage region, then backing pump operates effectively, but vibration increases affecting accuracy
Solution Approach 1:
The three-phase AC power supply and backing pump are extracted from the high-voltage region and placed in the low-voltage region. This removal eliminates the vibration sources associated with large motors operating at high voltage, thereby improving ion implantation accuracy. The backing pump remains effective by operating from the low-voltage region while receiving exhaust from the high-voltage turbomolecular pump through the voltage isolator.
Solution Approach 2:
The voltage isolator serves as an intermediary that allows the backing pump to operate effectively from the low-voltage region while handling exhaust from the high-voltage region. This arrangement enables effective vacuum pumping without introducing vibration-inducing three-phase motors into the high-voltage region, thus maintaining ion implantation accuracy.
4Weight of stationary object
If voltage isolator is used to separate backing pump from high voltage, then motor size is reduced, but system complexity increases
Solution Approach 1:
A voltage isolator is introduced as an intermediary component to connect the high-voltage turbomolecular pump exhaust to the low-voltage backing pump. While this adds a component to the system, it enables the use of standard-sized motors and power supplies, thereby reducing overall system complexity in terms of power conversion equipment and making the system more maintainable and cost-effective.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution reduces the need for bulky motors, lowers operational costs, minimizes vibration, and enhances the accuracy and reliability of the ion implantation process by maintaining vacuum conditions without the need for high voltage isolation transformers, while preventing Paschen discharge and ensuring safe operation.
Implementation Method 1
a voltage insulator that is insulatively coupled to the first backing line
Implementation Method 2
Vacuum conditions in components of an ion implanter are often created and maintained by a turbomolecular pump
Data Source
AI summary
In one embodiment a vacuum assembly for an ion implanter system includes a first turbomolecular pump operatively coupled to a source chamber of the ion implanter system and a first backing line having a first end and a second end, the first end coupled to an exhaust port of the first turbomolecular pump, wherein the first turbomolecular pump and first end of the first backing line are configured to operate at a voltage potential of the source chamber. The vacuum assembly further includes a voltage insulator that is insulatively coupled to the first backing line, and a second turbomolecular pump operatively coupled to the first backing line, wherein the second turbomolecular pump is configured to operate at ground voltage potential.