Photonics – Ion Beam Solutions

Several fabrication processes in photonics are discussed below. Please contact us for more technical discussions about your specific application!

Ion Beam Trimming – Uniformity Improvement:

Thickness uniformity is an important spec for many PIC applications. Ion beam trimming is a proven technology enabling volume manufacturing of highly uniform films.

The process is based on a physical sputter etch, and thus has been proven on almost all applicable materials. Please reach out to discuss your specific application or material!

The example below gives an example for trimming SiNx films.

Before After
Thickness Mean (nm) 465 446
Thickness Range (nm) 14 1
Thickness Uniformity 3.0% 0.2%
Roughness, Rq (nm) 0.41 0.22
Processing Time <5min per 200mm wafer

Ion Beam Sputtering – Si3N4 Waveguides:

Dual Ion Beam sputtering (DIBS) is the preferred process for depositing very precise and dense thin films. For Si3N4 deposition, an argon ion beam extracted from the primary source physically sputters a Si target. This sputtered material is combined with nitrogen gas (in the chamber or assist source) to reactively condense on the substrate as silicon nitride. The final film stoichiometry can be specifically controlled with process parameters. The assist source also serves as a pre-clean etch and as an additional energy source for further film densification during deposition.

  • Excellent uniformity <1%
  • High refractive index: 2.00 – 2.15
  • Extremely precise in-situ optical properties and thickness monitoring and control

Ion Beam Milling or Etching – Waveguides:

Waveguides for PIC applications require vertical and smooth sidewalls to satisfy optoelectronic properties. Certain waveguide materials, such as lithium niobate (LN, LiNbO3) and others, are difficult to etch and reach these specs with common ICP-RIE technologies. Ion beam etching (IBE) has been used for these materials in R/D and manufacturing to achieve the best optical devices.

Since IBE is a physical etching method, it is capable of etching all materials. F and Cl -based reactive gases can be supplemented to tune etch selectivities.

  • Directionality of etch
    • Vertical, smooth sidewalls
    • Slanted, smooth sidewalls
  • Excellent uniformity <1%
  • In-situ sidewall redeposition/fencing removal
  • SIMS or OES end point detection and etch material monitoring
  • Tiltable and rotatable substrate
  • He backside contact cooling with water
    • Chiller available for even lower temperatures
  • Capable of adding F- & Cl- gasses to Ar mixture for reactive ion beam etching