PECVD1 Wafer Coating Process

The wafers for process calibration are ordered from a wafer supplier that sells high grade, quality wafers. these are 4"Si wafers, with low particle count (Particles: <=10 @ >=0.3 microns). Wafers should be handled carefully, because every loading and unloading will add some particulates.

Surfscan 6200 (located in bay5) is used for scanning wafers. There are two standard recipes that could be used for scanning wafers: UCSBTEST1 (for scanning 8” wafers) and UCSBTEST2 (for scanning 4"wafers). The recipe UCSBTEST2 is used as a template to create other two standard recipes: "UCSB Gain4" (measuring small particles 0.16-1.6um) and "UCSB Gain2" (measuring larger particles 1.6-28um).

We have cassettes only for 4" and 8" wafers. If you plan to scan wafers that have different size, you need to provide your own cassette and calibrate it. If you need to scan wafer pieces, you need to develop your own procedure how to scan it.The section bellow describes how to run standard recipes for SiN and SiO2 at 250C in PECVD#1.

SiN @250C

1. Log in to PECVD #1
2. Seasoning
   • Load the seasoning recipe (SiN seasoning), and run it. The goal of this step is to coat chamber walls and prepare it for deposition.
3. Deposition
   • Vent the chamber and load the substrate (place it in the center of platen). You can place small pieces around the wafer to protect it from moving.
   • Pump down.
   • Load the deposition recipe (SiN@250C), and run it. Deposition time is variable. Get the rate from historical data.
   • Unload the wafer.
4. Cleaning
   • Wipe sidewall first with DI water, followed by IPA.
   • Load the cleaning recipe (CH4/O2 clean). Edit the recipe and enter required time for cleaning.
   • Log out

SiO2 @250C

1. Log in to PECVD #1
2. Seasoning
   • Load the seasoning recipe( SiO2 seasoning), and run it. The goal of this step is to coat chamber walls and prepare it for deposition.
3. Deposition
   • Vent the chamber and load the substarte (place it in the center of platen). You can place small pieces around the wafer to protect it from moving.
   • Pump down.
   • Load the deposition recipe( SiO2@250C), and run it.
   • Unload the wafer.
4. Cleaning
   • Wipe sidewall first with DI water, followed by IPA.
   • Load for cleaning recipe (CF4/O2). Edit the recipe and enter required time for cleaning.
   • Log out