Zinc sulfide

What Is Zinc Sulfide (ZnS) Sputtering Target?

Zinc sulfide sputtering targetis a compound ceramic material composed of zinc and sulfur in a near 1:1 stoichiometric ratio. It is widely used in physical vapor deposition (PVD) processes for producing optical and infrared thin films.ZnS is classified as a II–VI compound semiconductor with a wide bandgap of approximately:3.5 – 3.7 eV。This wide bandgap enables its use in optical coatings requiring high transparency from visible to infrared wavelengths.

ULPMAT provides high-density ZnS sputtering targets with controlled microstructure, low impurity levels, and stable deposition behavior for both research and industrial-scale PVD applications.Contact us.

Material Properties of Zinc Sulfide Sputtering Target

ZnS exhibits both semiconductor and optical ceramic characteristics depending on deposition conditions.

• Key physical properties:
• Chemical formula: ZnS
• Crystal structure: Zinc blende (cubic) / Wurtzite (hexagonal)
• Theoretical density: ~4.09 g/cm³
• Melting/decomposition behavior: ~1,185°C (partial decomposition under vacuum conditions)
• Bandgap energy: 3.5 – 3.7 eV
• Transmission range: ~0.4 µm – 12 µm (depends on film density & structure)
• Refractive index (n): ~2.2 – 2.5 at 550 nm
• Optical absorption increases significantly with:
• oxygen contamination > ~100 ppm
• sulfur deficiency in film growth

ZnS Sputtering Target Performance in Thin Film Deposition

ZnS targets are typically used in RF magnetron sputtering systems due to their compound nature.

Typical sputtering process window :
RF power density: 1 – 5 W/cm²
Working pressure: 2 – 10 mTorr (Ar atmosphere)
Substrate temperature: < 200°C recommended
Deposition gas: Argon (Ar), sometimes with controlled O₂ < 1–3%
Process behavior considerations:
Low pressure (<2 mTorr): higher film density but increased stress risk
High power (>5 W/cm²): increased sulfur re-evaporation risk
Elevated temperature (>250°C): stoichiometric deviation may occur

Why Target Density Matters for ZnS Sputtering？

Target density directly influences plasma stability and film quality.

High-density targets (≥95% theoretical density) provide:

• improved sputtering uniformity
• reduced particle generation
• better stoichiometric control

Lower-density targets may introduce:

• micro-void related arcing
• unstable deposition rate
• non-uniform thin film growth

Stoichiometry Control and Film Quality

The performance of ZnS thin films is highly dependent on Zn:S ratio control.

• Ideal stoichiometry: Zn:S ≈ 1:1
• Sulfur deficiency leads to:
  • increased optical absorption in visible range
  • degraded infrared transmission
  • higher defect density in film structure

FAQs

Q1: Why is ZnS mainly used in RF sputtering?
A1:Because ZnS is a compound semiconductor material that requires RF plasma for stable sputtering control.

Q2: What affects ZnS thin film optical quality most?
A2:Stoichiometry control and oxygen contamination are the most critical factors.

Q3: What is the typical substrate temperature for ZnS deposition?
A3:Usually below 200°C to avoid sulfur loss and composition deviation.

Q4: Why is high-density ZnS target important?
A4:Higher density improves plasma stability and reduces particle formation.

Report

Each batch is supplied with:
Certificate of Analysis (COA)
Technical Data Sheet (TDS)
Material Safety Data Sheet (MSDS)
Third-party testing reports available upon request

Why ULPMAT ZnS Sputtering Target？

ULPMAT provides engineered ZnS targets designed for stable thin film deposition:

• Controlled density and microstructure
• Stable sputtering performance
• Low contamination risk
• Consistent batch-to-batch quality