Technology of low pressure plasma

Nature as model!

Plasma is not a invention of humanity, it is formed in the tail of comets, in lightning at thunder storms, as well as in stars including our sun. Even northern lights are fascinating and well known occurrences of plasma. More than 99 % of visible matter in the universe is in the state of plasma, such as lightning, flames, northern lights etc.

The state of plasma is called the fourth state in addition to the liquid, solid and gaseous state.

This technology, which was already described in the last century, was a long time only an exotic niche. Through the rising understanding of the processes in and around plasma, this technology finds its way in rising numbers of laboratories and production facilities.

Because of the rapid development in the area of semi-conductor technology, the processes and technologies were even more refined and adjusted to the present technical requirements.

Today plasma processes are not only in the chip production, but also in many other industrial areas indispensable.

Plasma, especially low pressure plasma are already used in many places in plastics technology, micro technology, sample analysis or at the production of photovoltaic cells and displays. This technology is even in the medical area successful used.

Generally low pressure plasma is applied to clean samples, activate surfaces or to create coatings with functional layers via plasma polymerization. Thus the surfaces can be adjusted to the desired requirements.

Application and Equipment

In principle plasma processes can be classified in the following categories:

Cleaning, activation and coating.

To conduct a process under low pressure plasma the following technical equipment is needed:

Vacuum pump

To reach the needed low pressure in the process chamber of ca. 0,5 to 1,5 mbar, depending on application, so called dry running water meters or with oil greased vacuum pumps are employed. Particular attention is paid to the choice of oils. Especially at the utilization of oxygen as process gas, the application of oils specially suited for this process is recommended.

Induction of high-frequency

For initiation or ionization of the process gases, a high-frequency is inducted. For that purpose generators or magnetrons are applied with a frequency, which is approved by the lawgiver for technical utilization. In the process frequencies in the area of KHz, MHz and GHz are applied.

Each of these frequencies has its particular properties and should be chosen in accordance with its application..

Gas flow and measuring components

According to requirements, manual or electronic mass flow controllers are applied. Due to the reproducibility or at the application of gaseous mixtures, electronic mass flow controllers are required.

Plasma equipment of series AL

AL stands for aluminum chamber. This plasma equipment is mostly used in semi-conductor technology, solar-, plastics and electronic industry to activate plastics surfaces or to create ultrapure surfaces.

Application examples:

Pre treatment of metal and plastics parts prior to bonding, gluing, varnishing or printing. Micro cleaning of glasses, metals, ceramics or other vacuum suitable substrates.

Plasma equipment of series Q
Plasma equipment of series Q are mostly used in semi-conductor technology and in the area of analysis and medical technology.

Application examples:

Cleaning and incineration of organic samples and varnishes in micro mechanics as well as for silicium wafers in semi-conductor industry.