DRIE – SPTS Omega RAPIER 200 LPX

The SPTS Omega RAPIER plasma etcher is a Silicon Deep Reactive Ion Etch (DRIE) instrument designed for very high etch rate of Silicon using the BOSCH Process.

This tool allows anisotropic, fast and deep etching of Silicon (up to through-wafer-vias), ranging from 200mm wafers down to small chips, with very high selectivity with photoresist and silicon dioxide masks.

The tool comes with a manual, single wafer loadlock for ease of use in a research environment.

RIE uses chemically reactive plasma to remove material deposited on wafers. The plasma is generated under low pressure (vacuum) by an electromagnetic field. High-energy ions from the plasma attack the wafer surface and react with it. In ICP type of system, the plasma is generated with an RF powered electromagnetic field. Very high plasma densities can be achieved, though etch profiles tend to be more isotropic.

• High etch rates are achieved by high ion density (>1011 cm³) and high radical density
• Control over selectivity and damage is achieved by low ion energy
• Separate RF and ICP generators provide separate control over ion energy and ion density, enabling high process flexibility
• Low pressure processing yet still high density for improved profile control Chemical and ion-induced etching
• High conductance pumping port provides high gas throughput for fastest etch rates
• Fast mass flow controllers and pendulum valve allow very fast gas switching
• Electrostatic wafer clamping and helium cooling as standard, providing excellent temperature control

Schematic of an ICP RIE reaction chamber

• Inductively coupled plasma (ICP) power source: primary source for high density plasma generation and secondary source for uniformity adjustment
• Radio frequency (RF) power source: two frequencies available (HF or LF mode)
• Electrode temperature range: -10 °C to 20 °C.
• Process gases: octafluorocyclobutane (C₄F₈), and sulfur hexafluoride (SF₆), oxygen (O2), argon (Ar)
• Anisotropic etching of silicon

Supported Sample Sizes:

• Maximum wafer diameter: 200 mm (8 in).
• Small pieces supported: YES provided they can be glued to 8″ Si carrier
• Small wafers supported: to be discussed with tool manager

Typical Applications:

• Silicon etching with Bosch process.
• MEMS device fabrication.
• General device patterning.