PECVD-150LL & ICP-100 Enable Record-Speed PtSe₂/Si Photodetector

By NineScrolls Engineering · 2026-02-28 · 7 min read · Publication Spotlight

PUBLICATION SPOTLIGHT

Highlights

• Published in Applied Surface Science (Elsevier), February 2026
• PECVD-150LL deposited critical SiO₂ passivation layers; ICP-100 performed precision device patterning
• The photodetector achieves 260 kHz 3-dB bandwidth — the fastest reported for any PtSe₂/Si detector
• Successfully demonstrated polarization-encoded optical communication at telecom wavelengths

The Research

A team from Minnan Normal University, Fuzhou University, and Chalmers University of Technology (Sweden) has developed a CMOS-compatible p-PtSe₂/n⁻-Si/n⁺-Si PIN photodetector that establishes new performance benchmarks for two-dimensional material-based optoelectronic devices.

By integrating a highly oriented, near-stoichiometric PtSe₂ thin film (~32 nm) with a silicon PIN architecture, the researchers achieved self-driven broadband photodetection from 532 nm to 2200 nm, record-high 3-dB bandwidth, and the ability to decode polarization-encoded optical signals — key capabilities for next-generation optical communications and infrared imaging.

Reference:
Xu, X. et al., "Broadband and high-speed micro-scale PtSe₂/Si 2D-3D PIN photodetector for on-chip polarization-encoded communication and imaging," Applied Surface Science 730 (2026) 166329.
DOI: 10.1016/j.apsusc.2026.166329

The Role of Plasma Processing Equipment

Two plasma processing systems were essential to the CMOS-compatible fabrication flow described in this work.

PECVD-150LL — SiO₂ Passivation Layer Deposition

After transferring the PtSe₂ film onto the n⁻-Si/n⁺-Si substrate, a 20 nm SiO₂ protective layer was deposited over the entire PtSe₂/n⁻-Si/n⁺-Si stack using plasma-enhanced chemical vapor deposition (PECVD-150LL).

This passivation step is critical because subsequent fabrication steps — including oxygen plasma descumming for photoresist removal — would otherwise oxidize and degrade the PtSe₂ surface. The PECVD-150LL deposited a uniform, pinhole-free SiO₂ layer that preserved the 2D material\'s integrity throughout the entire downstream CMOS process flow.

ICP-100 — Precision Device Patterning

The ICP-100 inductively coupled plasma etcher was used in combination with RIE processing to define the device\'s critical features:

• Ring-shaped electrode contact windows (annular width: 10 μm) were etched through the SiO₂ layer to expose the PtSe₂ surface, enabling robust ohmic contact with subsequent metal electrodes
• Interconnect patterns for the 8 × 8 device array were precisely defined

The ICP-100\'s high-density plasma and precise etch control ensured accurate pattern transfer without damaging the underlying PtSe₂ thin film — a challenge that requires careful tuning of etch chemistry and power in 2D material device fabrication.

Figure 1: p-PtSe₂/n⁻-Si/n⁺-Si PIN photodetector architecture — PECVD-150LL provides SiO₂ passivation while ICP-100 defines precision device features

Key Performance Results

The 260 kHz bandwidth significantly exceeds all previously reported PtSe₂-based 2D/3D photodetectors, attributed to the PtSe₂ film\'s high crystallinity and the strong built-in electric field of the PIN architecture.

Demonstrated Applications

Polarization-Resolved Infrared Imaging

The photodetector successfully captured polarization-dependent current mapping images at wavelengths from 1310 nm to 2200 nm, with clearly distinguishable patterns across varying polarization angles.

Polarization-Encoded Optical Communication

Using a dual-mapping framework at telecom wavelengths (1310 nm and 1550 nm), the researchers demonstrated a polarization-angle-encoded communication system that successfully decoded all 26 letters of the alphabet — enabling secure free-space optical data transmission.

Equipment Used

• PECVD-150LL — Plasma-Enhanced Chemical Vapor Deposition system for SiO₂ passivation
• ICP-100 — Inductively Coupled Plasma etcher for precision device patterning
• Manufacturer: Beijing Zhongke Tailong Electronics Co., Ltd.
• Available through NineScrolls: View ICP Etcher Series → | View PECVD Systems →

Takeaway

This work validates that 2D transition metal dichalcogenides like PtSe₂ can be integrated into standard silicon CMOS fabrication flows to produce high-performance optoelectronic devices. The PECVD-150LL and ICP-100 played indispensable roles in this process — providing the precise thin-film deposition and plasma etching capabilities required to protect and pattern delicate 2D materials without compromising device performance.

As the field of 2D/Si heterojunction optoelectronics moves toward scalable manufacturing, reliable plasma processing tools like these become foundational to bridging the gap between lab-scale innovation and production-ready devices.

Interested in learning more about our PECVD and ICP systems? Request a Quote →

References

1. Xu, X. et al., "Broadband and high-speed micro-scale PtSe₂/Si 2D-3D PIN photodetector for on-chip polarization-encoded communication and imaging," Applied Surface Science 730 (2026) 166329. doi:10.1016/j.apsusc.2026.166329