Vacuum Systems

Vacuum systems are chambers where most of the gases present in the atmosphere have been removed by various pumping methods.  Processes typically performed in vacuum chambers are evaporation and sputtering. Evaporation is a thermal process which is usually instituted at the lowest practical pressure. Sputtering requires that after low pressure is reached a gas be reintroduced into the chamber at a low pressure before the process can be initiated.

Evaporation

Vacuum evaporation is the process of heating up a material in vacuum until it gets to the point of vaporizing at a rate suitable for film deposition. This temperature can range from far below room temperature to over 3000° Celsius depending upon the material. There is a lower practical limitation in the range of 750° Celsius to prevent contamination from one deposition process to the next.

Sputtering

Sputtering is the process of bombarding a material with heavy atoms or ions with sufficient energy to dislodge the material thus allowing it to transfer to a different location. The simplest form of sputtering is a DC target where the target of material is insulated from the vacuum chamber and connected to a source of high DC voltage. The high voltage creates a charge at the target surface and at the same time strips an electron from the sputtering gas (usually argon). Since the target has the opposite charge to the argon ion, the ions are attracted to the target and sputtering takes place as the argon ions impact the surface. It can be thought of as atomic level billiard balls. Modern systems are usually magnetron systems where a magnetic field close to the target creates additional ionization and hence higher sputtering rates.

Differences and Similarities

The appearance of sputtered or evaporated films is essentially identical. The energy imparted thermally (evaporation) is less than the energy imparted by sputtering, so sputtered films tend to be denser and better adhered than evaporated films. The distribution of sputtered material tends to be very broad due to the size of the target and also the fact that there are many atomic collisions taking place at sputtering pressure. All of the collisions change the direction of travel of material released from the target so sputtering tends to cover side walls of three dimensional objects. Evaporation is much more of a line-of-sight process which is preferable when it is not desirable to coat the side walls of structures.

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We supply vacuum thin film deposition services on customer-supplied substrates by SPUTTERING or EVAPORATION. Sputter coating is performed in Perkin/Elmer 4410 and MRC 603 and 903 sputter machines.

Electron beam evaporations are performed in modified CHA and Varian VACUUM SYSTEMS. All systems are cryopumped and housed in a Class 100 clean room. Substrates can be up to 12 inches square depending upon the system and material combination.

We are able to offer surface acoustic wave (SAW) device fabrication on piezoelectric materials such as quartz or lithium niobate. Ultrasound is one of our specialties with over 30 years experience with SAW devices and bulk piezoelectric materials such as PZT.

Our extensive materials and processing experience can be called upon to decide the best solution to your thin film needs.

MATERIALS INVENTORY - Deposition materials presently in our inventory, or which we are able to produce by reactive processes, include the following:

Sputtered films:
Ag, Al, Al-1%Si, Al2O3, Au, Co-80%Cr, Cr, Cu, Fe, Ge, Mo, Nb, Ni, Ni-20%Cr, Ni-7%V, Pt, Si, SiC, Si3N4, SiO2, Ta, TaN, TaSi2, Ta5Si3, Ti, TiN, TiO2, Ti-90%W, W, WN, WSi2.

Evaporated films:
Ag, Al, Al2O3, Au, CaF2, Cr, Cr2O3, Co, Cu, Dy, Er2O3, Ga, Ge, Hf, HfO2, In, Ir, ITO, MgF2, MgO, Mo, Nb, Ni, Pd, Pt, Re, Ru, Si, SiO, SiO2, Sn, SnO2, Ta, Ti, TiO2, V, Y, ZnO, Zr.

This list can be enlarged as targets or evaporation materials are purchased.