Metal Etch Scrubber

Explanation

The accumulation, transport, and processing of sewage results in the generation of harmful gases and odors. Chemical scrubbing is a gas scrubbing method in which contaminants are removed from the gas stream. During this process the gas stream passes through a packed structure with a large wet surface area. The wet area enables contact between the gas and the scrubbing chemicals and allows for removal of contaminants from the gas stream.

Mechanism

Aluminum etch systems use chlorine and boron trichloride gases to etch aluminum on wafer surfaces. The byproducts of the aluminum etch process include aluminum chloride that condenses in the downstream pump line and clogs vacuum exhaust lines. This reduces pumping speed and causes process variability and yield loss. The downtime required for periodic cleaning reduces throughput. In addition, solid boric oxide and boric acid are formed by the reaction of BCl3 with water vapor and oxygen in the exhaust line of the dry pump, clogging the entrance to the scrubber.

When a dry chemisorption scrubber is used, solid aluminum chloride often clogs its entrance, and contaminates its chemical adsorbent. Installation of a metal etch trap can extend the scrubber service life significantly.

The Metal Etch Trap, when installed as a component in an Effluent Management Subsystem™, efficiently traps condensable effluents that are generated by aluminum etch processes without reducing pumping speed. High trapping capacity means a longer time between maintenance. Maintenance is simplified by replacing a single disposable trapping element rather than cleaning many feet of vacuum line. Low cost of ownership is achieved by not running heated lines all the way to the scrubber.

 

Features

  • Increases throughput and uptime in metal etch processes
  • Decreases maintenance frequency and reduces maintenance time
  • Eliminates the use of heaters after the trap
  • Protects vacuum pump and valves
  • High flow conductance