BS1 - SPUTTER SYSTEM CHARACTERIZATION AND THE EFFECTS OF CHEMICAL ETCHING ON WHISKER PROPAGATION IN SPUTTERED SN FILMS
SCURS Disciplines
Mathematics
Document Type
General Presentation (Oral)
Invited Presentation Choice
Service-Learning — Oral
Abstract
Over course of this research cycle, we were able to finish manufacturing our new sputtering system (this included replacing two roughing pumps)! The system is now in working condition after some troubleshooting and adjustment of couplings. The system is currently able to reach low enough pressures for our current experiments, though further modification of the vacuum system (finding and sealing small leaks) may be necessary in the future when it becomes necessary that the system reaches 2 mTorr. We also made the electrical system more robust by redesigning the circuit and replacing the diodes with ones that can handle much higher voltages. We also created a casing for the rectifier circuit such that it is now secured to the sputter system housing, but can still be easily removed if necessary.
The sputter system itself is now complete and can reliably create strong plasma. We designed it with the goal of being able to adjust 1) the distance between the magnets and the sputter target, 2) the shape and strength of the magnets themselves, and 3) the spacing between the anode and cathode, where plasma formation occurs. We were able to achieve adjustability in all three of these areas. The area of the sputter head that houses the magnet provides around 1cm of adjustability for the magnet height, which should be plenty for determining the best magnet location. Further, we 3D printed different holders for each of the magnets/magnet combinations that we intend to test, as well as many thin spacers to be placed between the magnet and the sputter target for incremental adjustment of magnet spacing. Finally, the sputter head includes an adjustment nut that allows the user to move the cathode up and down with respect to the anode while maintaining vacuum pressure within the system, allowing for more efficient adjustments between trials.
In the near future, we hoping to build a pneumatic system that would allow for the use of argon in the sputter chamber where the amount of argon inflow would be adjustable. We have contacted the company about the parts list and we are almost ready to make the order and install the pneumatics.
In the experiment the magnet was tested in five different positions while the anode and cathode spacing changed five times per magnet position. The anode-cathode spacing increased incrementally by 0.25 mm in each position from the starting position of 1.46 mm. To measure this set of data, the whole system was set to a desired starting magnet position. The first set of data was with the magnet closest to the tin. A consistent starting distance for the anode-cathode spacing was chosen and set by a feeler gauge. After the pumps achieved low enough pressure, the potentiometer was set to 40 volts and turned on to charge the chamber and create plasma. At that point, a picture was taken to record the shape quality of the resulting plasma. The potentiometer was then turned off, and using the precisely marked knob, the cathode-anode spacing was increased by turning the knob precisely thirty degrees tighter. This process is repeated until 5 spacings are achieved. After data analysis, the conclusions are: 1) that the closer the magnet and the closer the anode cathode spacing, the more the plasma is stronger and better positioned around the tin plate, 2) as one moves the magnet away from the tin, the more spread out the plasma gets, and 3) the larger anode-cathode spacing, the dimmer the plasma is.
Keywords
Sputter, vacuum, Sn Whisker
Start Date
10-4-2026 2:10 PM
Location
CASB 102
End Date
10-4-2026 2:25 PM
BS1 - SPUTTER SYSTEM CHARACTERIZATION AND THE EFFECTS OF CHEMICAL ETCHING ON WHISKER PROPAGATION IN SPUTTERED SN FILMS
CASB 102
Over course of this research cycle, we were able to finish manufacturing our new sputtering system (this included replacing two roughing pumps)! The system is now in working condition after some troubleshooting and adjustment of couplings. The system is currently able to reach low enough pressures for our current experiments, though further modification of the vacuum system (finding and sealing small leaks) may be necessary in the future when it becomes necessary that the system reaches 2 mTorr. We also made the electrical system more robust by redesigning the circuit and replacing the diodes with ones that can handle much higher voltages. We also created a casing for the rectifier circuit such that it is now secured to the sputter system housing, but can still be easily removed if necessary.
The sputter system itself is now complete and can reliably create strong plasma. We designed it with the goal of being able to adjust 1) the distance between the magnets and the sputter target, 2) the shape and strength of the magnets themselves, and 3) the spacing between the anode and cathode, where plasma formation occurs. We were able to achieve adjustability in all three of these areas. The area of the sputter head that houses the magnet provides around 1cm of adjustability for the magnet height, which should be plenty for determining the best magnet location. Further, we 3D printed different holders for each of the magnets/magnet combinations that we intend to test, as well as many thin spacers to be placed between the magnet and the sputter target for incremental adjustment of magnet spacing. Finally, the sputter head includes an adjustment nut that allows the user to move the cathode up and down with respect to the anode while maintaining vacuum pressure within the system, allowing for more efficient adjustments between trials.
In the near future, we hoping to build a pneumatic system that would allow for the use of argon in the sputter chamber where the amount of argon inflow would be adjustable. We have contacted the company about the parts list and we are almost ready to make the order and install the pneumatics.
In the experiment the magnet was tested in five different positions while the anode and cathode spacing changed five times per magnet position. The anode-cathode spacing increased incrementally by 0.25 mm in each position from the starting position of 1.46 mm. To measure this set of data, the whole system was set to a desired starting magnet position. The first set of data was with the magnet closest to the tin. A consistent starting distance for the anode-cathode spacing was chosen and set by a feeler gauge. After the pumps achieved low enough pressure, the potentiometer was set to 40 volts and turned on to charge the chamber and create plasma. At that point, a picture was taken to record the shape quality of the resulting plasma. The potentiometer was then turned off, and using the precisely marked knob, the cathode-anode spacing was increased by turning the knob precisely thirty degrees tighter. This process is repeated until 5 spacings are achieved. After data analysis, the conclusions are: 1) that the closer the magnet and the closer the anode cathode spacing, the more the plasma is stronger and better positioned around the tin plate, 2) as one moves the magnet away from the tin, the more spread out the plasma gets, and 3) the larger anode-cathode spacing, the dimmer the plasma is.