- General Description
- The LF001 is a barrel plasma etcher that uses oxygen to etch organic films and residues such as photoresist in a process commonly referred to as "descumming."
- During a normal run for the LF001 Etcher, the chamber is evacuated to under 0.5 torr pressure. A regulated flow of oxygen gas is introduced into the chamber and RF energy is applied to the chamber coils, which creates an oxygen plasma which does the etching. The oxygen ions in the plasma react with organics, such as photoresist, oxidizing or descumming the compounds off of the surface. The oxidized organics are pumped out of the LF001 Etcher's chamber as exhaust gas.
- Operating Instructions
- Turning on the necessary equipment
- Make sure the house nitrogen is on.
- The oxygen tank is located in the back pump room. Turn it on with the valve on the top of the cylinder.
- The vacuum pump for the LF001 can be switched on and off with the switch box mounted on the wall to the left of the LF001. Make sure no one uses the PE2 while you are using the LF001 - they use the same vacuum pump. (The vacuum pump for the LF001 is the fourth machine on the right when you enter the pump room.)
- Make sure all Power switches are in the "OFF" position and the RF power turned counter-clockwise.
- The "MANUAL/AUTO" switch should be in the MANUAL position.
- The "Vacuum" and "Purge" switch should be in the AUTO (down) position.
- Turn on the "AC POWER" switch on the power supply below the table. Make sure the "Ready" light on the generator must be illuminated for operation. This can take up to three minutes.
- Turn on the "AC" switch in the lower-left corner of the control box.
- Loading the chamber
- 1. Turn on the nitrogen to vent the chamber with the "PURGE" switch.
- 2. DO NOT FORCE THE DOOR OPEN! It should open easily when the pressure has equalized.
- 3. Turn the "Purge" switch to AUTO (down) and load your wafers into the boat.
- 4. Close the door and turn on the "Vacuum" switch.
- Manual Run
- Note - In manual mode, the timer is disabled!
- 1. After less than a minute of pumping, the pressure on the torrmeter should be less than 0.5 torr.
- 2. Turn on the "GAS 1" (Oxygen) switch to start the oxygen flowing. Use the valve on top to adjust pressure. CAUTION: Do NOT use the flow adjust needle valves to completely turn off the gas flow, it may permanently damage the valve.
- 3. Turn on the "RF POWER" switch. After 10 seconds, the RF will actually turn on, and the needle on the RF power gauge will rise.
- 4. Make sure the switch under the RF gauge is in the "FWD" (up) position. Use the knob to set the power to 200 Watts. WARNING!!! DO NOT SET THE POWER ABOVE 300 WATTS!
- 5. When finished, turn off the "RF" and "GAS" switches.
- Venting the Chamber
- 1. After finishing a process, wait for the vacuum to pump down to under 0.5 Torr.
- 2. Turn off the "VACUUM" switch.
- 3. Turn on the "PURGE" switch.
- 4. Turn off the "PURGE" switch when the chamber is at atmospheric pressure and remove your wafers.
- Auto Run
- With an auto run, the machine turns off the power and the gas when the timer runs out.
- You must have programs ready to go; these have not been provided. For plasma etching or cleaning wafers, running the machine in Manual mode is much easier.
- Shutting down the LF001
- 1. Turn on the "VACUUM" switch and pump the chamber down to under 0.1 Torr.
- 2. Turn off the "VACUUM" switch.
- 3. Turn off the "AC" switch on the control box and the "AC POWER" switch on the power supply below the table.
- 4. Turn off the oxygen in the back and the vacuum pump.
- 5. If you are the last one to leave the cleanroom at night, shut off the house vacuum and the nitrogen as well.
- Etch Rates
- 1. AZ 3330 - 46 nm/min 200 W, 100 O2 flow
- 2. AZ 2020 - 62.8 nm/min 200 W, 100 O2 flow
- 3. SU 8 - 56 nm/min 200 W, 100 O2 flow