# Manual for Spin coating and Alignment
### Resevation
Reserve on [google calendar]( ) from Prof. Shinhyun Choi’s lab

## Spin coater
1. Turn on the power switch. It's on the back side of the machine.
3. Open the lid, make sure to flip it over.
It can prevent contamination.
3. Use aluminum foil to cover the inside of container, to prevent the liquid contamination and make easier to clean the machine after using.
4. Prepare the sample, and put it on the center, the set it to vacuum.
You can see “vacuum on” button on touchscreen
5. Cover the Photoresist(PR) on the sample
If you caused bubbles on the sample, remove it by your dropper
6. Close the lid, and choose the recipe you want. Then press start button.
7. After finishing, open the machine and turn off vacuum.

* Make a small plate by aluminum foil to store the samples.

## Soft bake
- Using Hot plate
1. Press the button, then turn on the hot plate.
2. Remember to set temperature (depends on recipe) by rotating the button.
If you change the set temperature, wait until the temperature stabilized
3. Just put the sample on the hot plate. Then counting.(depends on recipe)

- Using oven
1. For soft bake, Prof. Shinhyun Choi’s lab uses 90℃, 3min.(Use stopwatch)
2. While waiting for soft bake, it's better set up the aligner.
UV light takes some time to be turned on.

## Alignment and Exposure
1. Main power is in the back side. It’s usually turned on, but please check every time.
2. Turn on the auxiliary switch. It’s on the front side.
3. Turn on the PC and UV lamp power supply. It’s under the desk.
4. UV lamp power supply has 6 buttons. Press the upper-left button, then you can see
Voltage/Current/Power on the screen. You have to wait until power reaches 200W.
5. When the PC is on, the microscope program will automatically open.
6. To open the mask / sample holder, click the "MASK HOLDER LOCK" button on PC.
7. Put the mask on the mask holder(left), then press the mask vacuum button on the machine to stick the mask.
It’s better to use physical button rather than PC. If you use physical button, MASK VACUUM button in PC is deactivated, and it prevents you to click the button by mistake and mask doesn't drop on the sample.
If the number on screen is around -550, it means well-vacuumed. If not, turn off the vacuum and try again(check the probable resaons, might be the small dust on the machine or your sample, so just use the blower to remove it, might be that your sample position is not right, then totally remove it from the machine and put it back again).
8. Put you sample on the center of the sample holder(right), then click SAMPLE VACUUM button on PC.
9. Close the aligner, then it will be automatically locked.
10. Click the "ALIGN" button, then the microscope starts working. Click N~2~ LOW button. It makes the sample and the mask to be separated.
11. When you align the sample, check by your eyes if the position of mask is near the center of the sample first.
12. You can move the sample stage with below micrometers. Move the sample in z-direction and make the sample sticked on the mask. When sample is sticked well on the mask, it doesn’t move smoothly in x- or y-direction. And click WEDGE LOCK button. Then move the sample below a little bit to align the pattern.
13. When aligning, use the rectangular pattern in the corner first, then use double-cross pattern. Move the sample in x-y direction and rotate to align the pattern. To make better alignment, repeat this process at high magnification of microscope. (Please make the focus and illumination right)
You can change the lens of the microscope(2x magnification, ENTIS has this.) to make better alignment.
14. After alignment is done, move the sample in z-direction. The sample can be out of alignment while moving in z-direction. Re-align the sample during moving in z-direction.
15. After the sample is sticked well on the mask, press "VACUUM CONTACT" button.
Instead, you can use Hard contact button. It blows nitrogen from below the sample.
For fine pattern, vacuum contact is better, but mask can easily be dirty.
16. Click the EXPOSURE button, then set the exposure time. And click SHUTTER button.
When exposure, do not look at the UV light to protect your eyes.
17. When UV exposure is done, unlock the wedge, and click N~2~ HIGH button. It helps to seperate the sample and the mask. When it's suddenly on, it will make noisy sound because they are well sticked. After moving the sample stage in -z direction slowly, the sound will be smaller since the gap gets bigger.
18. Open the aligner, and turn off the sample vacuum.

## Post bake
1. Put your sample in the baker with right temperature.
For post bake, Prof. Shinhyun Choi’s lab uses 110℃, 3min.(Use stopwatch)
* You can change the temperature value, but if you changed the temperature,
wait until temperature is stabilized.

## Develop
1. Prepare the face guard, and developer chemical(ex : AZ300MIF), DI water in beaker.
2. Put samples on the sample holder, but you’d better not use the front side of the sample holder. It causes bubble and disturbs the develop process.
3. Put sample holder in the developer and stir it for 30 seconds.
4. After 30 seconds, transfer the sample holder in the DI water beaker, and wash each sample with water using water faucet.
5. Use N~2~ gun to blow the water from samples.

* Check the sample with microscope again

## After using
1. During Post Bake process, if there is no one using the aligner after you, it’s better to turn off the aligner because it takes time for UV lamp rest(about 30 minutes).
2. After the rest time, turn of the UV lamp power supply, then turn off the microscope program and PC.
3. If your mask is too dirty, clean it with acetone first, then clean it with IPA, then with DI water.
4. For spin coater, clean the chuck with acetone, and clean the lid with IPA (do not use acetone because it's plastic).