PECVD 1 (PlasmaTherm 790)

PECVD 1 (PlasmaTherm 790) Tool Type Vacuum Deposition Location Bay 3 Supervisor Brian Lingg Supervisor Phone (805) 893-8145 Supervisor E-Mail lingg_b@ucsb.edu Description PECVD Plasma Therm 790 For Oxides And Nitrides Manufacturer Plasma-Therm Vacuum Deposition Recipes

About

This is a Plasma-Therm model 790 plasma enhanced chemical vapor deposition system for depositing SiO₂, Si₃N₄, or SiO_xN_y dielectric films. The system uses a capacitively-coupled 13.56 MHz source excitation to produce the plasma between two parallel aluminum plates. The gas is injected over the sample through a 6” diameter showerhead. The samples are placed on the system anode (to minimize ion damage) which is heated to 250-350°C. SiO₂ is produced from SiH₄/He 2%/98% and N₂O at 250°C. The typical deposition rate is 400 A/min. at 300 mT pressure. The typical BOE etch rate of this oxide is about 400 nm/min. Si₃N₄ is produced from SiH₄/He 2%/98% and NH₃ at 250°C or 350°C. The more dense films are produced at 350°C. The stress of the nitride can be altered by adjusting the N₂:He ratio of the deposition. CF₄/O₂ plasmas are used to clean the chamber between depositions.

These films are typically used for capacitor dielectrics, chemical passivation layers, electrical insulators, reactive ion etching masks, and optical anti-reflective coatings. The system is fully programmable with windows-based software and has a wide array of pre-defined thicknesses. Custom programs for dielectric stacks or different process parameters can be written and saved.

Detailed Specifications

• Gases used: NH₃, N₂O, 2%SiH₄/He, N₂,CF₄ and O₂
• ~ 10mT ultimate chamber pressure
• 13.56 Mhz excitation freq.
• Sample size: pieces to 6” wafers
• Automatic tuning network
• RF Power control
• Full computer operation
• Standard recipes for a variety of film thicknesses