In-situ end-pointing metrology solutions for monitoring dry etch processes

Within the frontend process chain, dry etch processes are crucial for obtaining high perfomance devices at the end of production. Similarly to epitaxial processes, LayTec is offering a reflectance-based metrology solution for monitoring etch processes – with a particular focus of end-pointing methods in general and within-layer-endpointing in particular. With these methods it becomes possible to stop the etching processes at the desired etch depth with an unrivalled sub-nm accuracy, independently of the existence of a material interface, thus, enabling superior device performances.

Metrology Solution:

LayTec’s metrology portfolio comprises solutions for both dry and wet etching processes. For dry-etching, TRIton enables sub-nanometer accuracy within-layer end-pointing for etching into layers of GaN, AlGaN, InP, GaAs and many more which would never be achievable with plasma-based methods. By selecting appropriate wavelengths for a given material system the etch progress can be monitored with an unmatched accuracy. Depending on the etch rate and the responsivity of the etch tool precision levels even in the subnanometer range can be reached. These unprecedented precision levels for dry-etching are only achievable due to LayTec’s modular design and advanced algorithms our methodology allows. For end-users, the TRIton system also comes with our dedicated EtchNet software for analyzing the process data in order to get the most out of your measurements.

For Atomic Layer Etching, with ‘Etchpoint’ a particular OEM solution for Oxford Instruments Plasma Technology etch chambers is available which enables sub-namometer-accuracy endpointing during AlGaN recess etching .

Generally, the following products are available for in-situ monitoring of etch processes:

  • TRIton
  • Etchpoint (OIPT OEM)

Product information

  • Etch depth determined on dedicated measurement pads as small as (50µm x 50µm)
  • Within-layer endpoint detection (EPD) with sub-nanometer accuracy
  • For Atomic Layer Etching (ALE) sub-nm precision is obtained
  • Auto-correction for all plasma influences during dry etching
  • End-point solutions for wet etching processes