FAQ on Rapid Thermal Processing Systems:
1. Q: Which model should I purchase?
A: Normally your biggest substrate size determines the model. AW 410 is up to 4 inch;AW 610,AW 610V are up to 6 inch; AW 810,AW 820, AW 820V are up to 8 inch.
2. Q: Can I use AW 610,AW 810 for 2 inch substrate?
A: Yes. You can run 4 pieces of 2 inch on AW 610 and 16 pieces of 2 inch on AW 810 in one batch.
3. Q: Which type of RTP should I purchase, Atmospheric or Vacuum?
A: You can run most processes by Atmospheric RTP. Atmospheric RTP has much better performance ( repeatability, stability, uniformity) than vacuum RTP because of atmospheric RTP’s compact chamber design, isolated quartz tube, top&bottom lamp heat, pure gas purge, 30 years approval. The ownership cost and usage cost of Atmospheric RTP are lower. If you are not sure that you have to use vacuum RTP because of O2, you can buy atmospheric RTP with forming gas to get 2 to 12 PPM O2 environment instead of vacuum RTP.
4. Q: What are the differences in Allwin21 vacuum RTPs?
A: AW 610V is up to 6 inch wafer. It comes with only cross top lamp heat. The maximum temperature is 1000C @ 2 minutes. AW 820V is up to 8 inch wafer. It comes with top and bottom lamp heat.The maximum temperature is 1250C @ 10 minutes. AW 860V is automatic system with reliable robotic wafer transfer. AW610V & AW820V are manual loading.
5. Q: Should I have to use susceptor for transparent substrate?
A: Normally transparent substrate can not absorb lamp heat since it is transparent. You have to use carrier which can absorb lamp heat and transfer the heat to transparent substrate. Susceptors can be made of SiC, Silica,Graphite,or Si. They can be costly. You can use a Si wafer as carrier if your process is applicable. You can us a Si wafer with pocket, instead of susceptor, if your budget is tight. A susceptor will lower the ramp rate and cooling rate significantly because of its size and thickness.
6. Q: Which material of susceptor should I purchase?
A: Traditionally people use graphite with SiC coating for susceptor. Graphite susceptor is for up to 900C with lower ramp rate. Silica susceptor is for up to 1100C with higher ramp rate. Sintered SiC susceptor is for up to 1100C with lower ramp rate. Si susceptor is less expensive and up to 750C with lower ramp rate. The bigger the size of susceptor, the lower the ramp&cooling rate.
7. Q: Should I purchase an ERP Pyrometer as high temperature sensor?
A: Thermocouples (TC’s) are the traditional temperature sensor for lower than 1050C. But TC will react with Si wafer at 750C. Our patented ERP Pyrometer can work at 450~1250C with precise measurement after calibration by AW technology. TC has to contact the substrate for temperature measurement while ERP Pyrometer is non-contact. TC cost is lower while ERP Pyrometer’s is higher (more than $15K with calibration tools (TC wafer and omega meter). TC will evaporate at high temperature causing contamination.
8. Q: Can I measure the temperature uniformity by multiple points TC wafer?
A: If the temperature is lower than 500C, you can measure the temperature uniformity by TC wafer directly. If the temperature is higher than 500C, you have to measure other parameters’s uniformity to reflect the process uniformity. The influence of lamp, chamber, the structure of TC wafer etc is significant at higher than 500C. Semiconductor industry measures sheet resistance. LED industry measures voltage.
9. Q: Can I have a demo before purchase?
A: We have demo systems in our facility in USA. We can do demo one time for you if you can send your wafer to us and our facilities are applicable. But be aware that you cannot evaluate the performance by one demo result because of the following. (1) The demo condition might not be good enough; (2) Your recipe parameters might not be applicable because RTP temperature number in recipe is relative, not real.
10. Q: What is the most important feature for RTP system?
A: Repeatability. If the RTP system performance is not repeatable, the RTP will be “Rapid Trash Process”.
11. Q: How many gas lines can Allwin21 RTP come with?
A: AW 410, AW 610 come with 1, or 2 to 4, or 5 to 6. AW 810, AW 820,AW 830 come with 2 to 4 lines. AW 610V,AW 820V,AW 860V comes with 2 to 3 lines. Customizing is optional. The popular MFCs are 10 SLM N2, Ar, O2 and 5 SLM NH3, N2O2.
12. Q: Can customer install the RTP by themselves?
A: Yes. Our RTP systems are customer-install design. We sold our RTP systems to more than 40 countries. Most customers installed our RTP systems by themselves according to our professional manuals. We provide free technical supports by email, phone, skype etc. We have local reps who can provide 24/7 service in some countries.
13. Q: Why should we purchase an RTP from Allwin21?
A: (1) Best repeatability
(2) Our system hardware and software technology have been approved based on 30 years of semiconductor industry development.
(3) It can cost a lot money and time to test an unpopular or new RTP systems .
(4) Allwin21 focuses on RTP as our main business. We professionally provide high quality RTP system and technical support.
(5) Reasonable price accepted by 40 countries’ clients.
(6) Industry-leading lead time (2 to 4 weeks).
