pecvd

Plasma Enhanced CVD

Plasma Enhanced Chemical Vapour Deposition (PECVD) can be used to deposit SiO₂, Si₃N₄ (Si_xN_y), Si_xO_yN_z and amorfous Si films at relatively low temperatures between 100ºC and 400ºC.
PECVD films find their applications for example as scratch protection layers and isolation layers.
The PECVD process uses not only thermal energy to initiate and sustain chemical reactions, but also an RF-induced glow discharge to transfer energy to the reactant gases (e.g. SiH₄, N₂O, NH₃). Mostly a carrier gas (N₂) is used. This allows the substrate to remain at a substantial lower temperature compared to Low Pressure CVD (LPCVD). The glow discharge, generated by a RF-field to a low-pressure gas, creates free electrons within the discharge region with enough energy to dissociate the reactant gases in order to form the solid film on the substrate.

The main advantages of PECVD processing are:

Low deposition temperature
Good dielectric properties of the films
Low mechanical stress
Good conformal step coverage (see Fig. 1)

Fig. 1
Conformal step coverage of PECVD Si_xN_y

Novellus C1-200

The Novellus Concept1-200 was originally designed as a high-throughput production machine, capable of handling only one wafer size. However adapting the cassettes made it possible to handle wafer diameters of 100, 150 and 200 mm. Smaller substrates (parts), up to 139 mm diameter, can be processed also using a special holder.
The system consists of 5 different deposition positions making it a dynamic PECVD process; dynamic in the manner that the deposition of the total layer happens via 5 consecutive depositions each consisting of 1/5 of the total layer thickness. The main advantages of this system are the high throughput, a very uniform layer thickness and (almost) pinhole free film. The deposition temperature is limited between 200ºC and 400ºC.

STS Twin
The STS-twin is a static run PECVD machine.
It can handle all kind of wafers, sizes and dimensions up to a diameter of 400 mm.
Substrate temperatures are in the range off ca 80 – 400°C.
The stress can be tuned by adjusting the plasma frequency.

AKT 1600

The AKT 1600 has a background in LCD processing and can handle plates with size 355 x 400 mm^2. Smaller sizes can be handled on carrierplates.
The machine consists of 3 process chambers and one heat chamber. Particle free deposition is guaranteed by plasma cleaning of the process chamber after every deposition. The machine is suitable for process photo voltaic processes and LCD processes. This machine can produce high quality SiN, SiO and (doped) amorphous Si layers.