SiNx PECVD Process

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Material Properties and Applications of Silicon Nitride (SiNx)

Silicon Nitride (SiNx) is a chemical compound of the elements Silicon and Nitrogen.
SiNx has unique chemical and mechanical properties including low moisture and oxygen permeation, good electrical insulation and low thermal expansion.

For device fabrication, this material is used for various purposes.
• Passivation
• Insulation layer
• Mask for dry etching and ion implantation

Periodic Table (SiN)

By adjusting process recipe (pressure, RF power and etc.), SiNx film properties (wet etch rate, refractive index, film stress and etc.) can be controlled.
SAMCO offers both Anode PECVD and Cathode PECVD process solutions for SiNx thin film deposition.
For more detail on Cathode PECVD technology, please visit our Featured Solutions Page.

Conformal SiNx Passivation Film Deposition

SiH4 based SiNx film was deposited for passivation of organic light emitting diode (OLED) fabrication, using an anode-coupled PECVD system. The film showed excellent step coverage on a structure over 90° step.

Deposition Temperature : 100°C
Film Thickness : 1.16 µm
Deposition Rate : 23.3 nm/min

SiN Film Deposition with Excellent Step Coverage

Control of SiNx Film Properties

SAMCO’s SiNx PECVD technology shows a highly-controllable wide process window and reproducibility with adjustment of process recipe.
The deposition processes are suitable for R&D to satisfy various demands on device fabrication.

Film Stress

Stress Control of SiN Film

Process Pressure v.s. Film Stress
SiH4 based SiNx using an anode PECVD system

Refractive Index

Refractive Index Control of SiN Film

NH3 Flow Rate v.s. Refractive Index
SiH4 based SiNx using an anode PECVD system

Wet Etch Rate

Wet Etch Rate Control of SiN Film

Stage Temperature v.s. Wet Etch Rate
SiH4 based SiNx using an anode PECVD system

Safe SiNx Plasma Deposition without Using SiH4

Challenge in SiH4 Based SiNx PECVD Process

Silane (SiH4) is widely used for PECVD processes to obtain high quality films. One of the drawbacks of a SiH4-based PECVD process is the safety issue. SiH4 is a flammable gas and easily ignite on contact with air. Also, the gas has toxicity to the human body. Therefore, device manufacturers need to take care of the gas use in production lines in the aspect of environment, health and safety (EHS).

SN-2 Based SiNx PECVD Process

SAMCO provides SiNx PECVD process solutions using liquid source called SN-2. SN-2 is an inorganic material which is available as liquid at room temperature. This material is not pyrophoric in air compared to SiH4, and there is no need to heat up a container to use for deposition processes. SAMCO offers SN-2 based SiNx deposition processes of both Anode PECVD and Cathode PECVD, depending on customers’ process requirements.

SN-2 based SiNx can be used for an alternative of SiH4 based SiNx at existing wafer fabs concerning the safety issue. SiNx films from different precursors were deposited using an anode-coupled PECVD system to investigate chemical bonds of the films. The FTIR transmittance spectrum showed peaks of Si-H, N-H and Si-N on the SN-2 based film, and they are seen as well in the spectrum of the SiH4 based film. This means that the SN-2 based film has quality as good as SiH4 based SiNx film.

SiN Film Deposition Using Liquid Source

 FTIR spectrum of SiH4 based SiNx and SN-2 based SiNx

SN-2 Based SiNx Film as Hard Mask for Plasma Etching

One of the common applications of SINx film in today’s micro-electronics fabrication process is hard mask for plasma etching and ion implantation. SN-2 based SiNx film is a good option in hard mask deposition for R&D labs which have severe restriction in hazardous SiH4 use. SN-2 based SiNx film shows controllable BHF etch rate as good as SiH4 based film. BHF etch rate can be lineally controlled with precursor flow rate adjustment.

BHF etch rate of SiH4 based SiNx and SN-2 based SiNx

BHF etch rate of SiH4 based SiNx and SN-2 based SiNx (against thermal oxide)

Controllable SN-2 Based SiNx Film Properties

The SN-2 based SiNx film shows excellent film properties. Film stress is lineally controllable with adjustment of deposition recipe. Furthermore, the step coverage is remarkably good.  The film deposited on Al lines showed conformal coating on vertical sidewalls.

In addition to Anode PECVD process, SAMCO’s unique Cathode PECVD Technology will offer high-rate deposition of dense SiNx film, utilizing ion bombardment driven by the negative electric field of the cathode electrode.

Stress Control of Liquid Source SiN Film

Stress control of SN-2 based SiNx

Step Coverage of Liquid Source SiN

Step coverage of SN-2 based SiNx on Al lines

System Lineup for SiNx PECVD

Anode PECVD Systems

– Superior process control 

Anode PECVD Systems


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Cathode PECVD Systems

– High-rate deposition of SiNx using high ion energy 

Cathode PECVD Systems for high-rate SiNx deposition


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  • SAMCO PECVD System for SiN deposition


 SAMCO’s SiNx PECVD technologies are used for device fabrication and material research at nanofabrication facilities including

University of Science and Technology of China

Any Questions?

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