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The Plasmatherm 790 is a dual chamber parallel plate tool. The left chamber is configured for reactive ion etching (RIE) while the right chamber is configured for plasma enhanced chemical vapor deposition (PECVD). The RIE chamber is significantly slower than other etchers available in the lab, allowing greater depth control on thin films. The PECVD chamber is also designed to deposit at a lower rate than the GSI PECVD and P5000 PECVD - the smaller building blocks help improve film quality. This tool has almost no material restrictions, allowing a wide variety of processing.

Plasmatherm 790
Equipment Details
Technology RIE
Materials Restriction Metals
Material Processed Si, SiO2
Mask Materials PR, SiO2
Gases Used

Ar, CH4, CHF3, CF4,

H2, O2, SF6
Equipment Manual
Overview System Overview
Operating Procedure SOP
Supported Processes Supported Processes
User Processes User Processes



  • Wide variety of materials processed
  • Wide variety of gases available
  • Generally slower etch rates <1000 Å/min
  • Generally slow PECVD deposition rates <10 Å/sec

System Overview

Hardware Details

  • Pressure
    • RIE: 1 Torr Guage
    • PECVD: 2 Torr Gauge
  • Chuck
    • PECVD: Heated Platen: 200°C - 350°C
  • RF
    • 400 W 13.56 MHz RF Source

Substrate Requirements

  • RIE
    • Up to 3 100 mm (4") wafers
    • Pieces don't require mounting
    • 1 150 mm (6") wafer
    • 2 100 mm (4") wafers
    • Several pieces

Material Restrictions

The Plasmatherm 790 is designated as a metals class tool. Below is a list of approved and restricted materials for the Plasmatherm 790. "Approved" means the material is allowed in the tool under normal circumstances. "Not Allowed" means the material may never be used in the tool. If a material is not listed, it may be possible to use the material under certain conditions. Please contact a tool engineer via the helpdesk ticket system for any material requests or questions.

Left Chamber

Right Chamber

The right chamber has the same restrictions as the left except polymers (such as photoresist) are not allowed unless their melting temperature is significantly higher than the process temperature (please create a helpdesk ticket for this).

Supported Processes

There are several processes for this tool supported by the LNF, which are described in more detail on the Processes page.

In addition to these, this tool has a number of user-created recipes for etching a wide variety of materials. Some of these recipes are documented on LNF User:Plasmatherm 790 User Processes. If you are curious if your material can be processed in this tool, please contact the tool engineers via the helpdesk ticket system.

The latest PECVD qualification data is shown below.

Standard Operating Procedure

Checkout Procedure

  1. Read through the User Manual above.
  2. Accurately complete the SOP quiz. You may retake as necessary until all answers are correct.
  3. For RIE, complete the process request form.
  4. Create a helpdesk ticket requesting a checkout session.
  5. Authorization will be provided pending successful completion of the quiz and demonstration of proper tool use in the presence of a tool engineer.