RFP A21-0900 Addendum 1 - Questions Submitted and Answers Provided.pdf

RFP A21-0900 Pulsed Laser Deposition System

Addendum 1- Questions Submitted and Answers

02/08/2021

1. Gas lines are specified. What gases will be used?

2. Our systems usually have at least two gas capability. How many gases are required for the PLD system?

Answer to 1 and 2 – Inert gas argon (Ar) and reactive gas nitrogen (N2) will be used.

3. What is the specified substrate temperature? Or is the substrate at room temperature?

4. Typically, PLD systems utilize a heated substrate carrier. The specifications do not ask for heat. Is heat required, and if so, what heater temperature is needed?

Answer to 3 and 4 - The ability to control the substrate temperature from room temperature up to 800 °C is required.

5. 70 l/sec turbo pump is specified for 5 x 10-10 base vacuum. Given the volume of the chamber (~40 ltrs), the specified pump with a pumping speed of 70l/sec is too small for this application.

6. The 70 l/s pump is extremely small, especially if the upgrades listed for future expansion are added. Is there a provision to add a larger pump in the future, or should we list a larger pumping stack as an option?

Answer to 5 and 6 - Ultra high vacuum (5 x 10-10 Torr) is required. Therefore, please quote the pump that will sustain it.

7. Is it mandatory to use a cylindrical shape chamber as specified.

8. The chamber is described as a cylinder. Is a spherical chamber acceptable?

Answer to 7 and 8 - The chamber is described as a cylinder. Is a spherical chamber acceptable?

No preference, spherical shape is acceptable.

9. A minimum fluence of 1 J/cm2 or a minimum pulse energy of 80mJ (at 248nm), will be too small for ablating intermetallic materials with high reflectivity for 248nm wavelength. Please clarify.

Answer - Please quote the laser that can ablate metals and alloys (fluence of >10 J/cm2).

Materials planned to be used as a targets are rare earths (La-Lu), transition metals, and p-elements (Si, Ge), as well as their alloys and intermetallic compounds.

10. We can provide either an open loop pressure control scheme (less expensive), or a closed-loop pressure control scheme (more expensive). Which one is required?

Answer - Open-loop pressure control will suffice. Please quote both for comparison.

11. We can supply either rotameters or MFC’s for the gases. Which one is preferred?

Answer - We prefer MFC’s. Please quote both for comparison.

12. A 1” wafer is listed as the sample size. Is this the only substrate that will be used?

Answer - Yes, 1” should be sufficiently large for our needs.

13. A small substrate is typically bonded to the substrate carrier using a thermal paste, and a large substrate is typically held in place utilizing a mechanical mount. How is the substrate to be held onto the carrier?

Answer - Thermal paste is OK, as long as it can withstand heating up to 800°C. We plan on using 1” wafers.

14. A base vacuum of <5x10-10 Torr is listed as a requirement. How long does the system to reach the specified vacuum?

Answer - Not critical, can be long if needed.

15. Is there a space restriction in the lab where this system will reside?

Answer – No space restrictions.

16. We offer an integrated laser frame, which allows the main system to connect directly to the PLD system. Will a table be provided, or should we quote the integrated frame?

Answer - Please quote the integrated frame.