Semiconductor Metallization Disposition Processes

During the manufacturing of semiconductors, the vacuum metallization process is used to link together circuits. This is done by placing a thin layer of film made from a metal such as aluminum, nickel or gold between the elements of a semiconductor. While the end goal is to create an electrical connection between components, there are different ways to achieve this.

Here is a look at some of the common metallization disposition processes for semiconductors:

Sputtering: A sputter coater places a thin film by bombarding the target material with ions of an inert gas. The gas is introduced into a low-pressure vacuum while an electric field charges the ions and draws them to the target. Sputtering allows for a high level of control over the dispersal of the coating and can be used in almost any semiconductor application.

E-Beam Evaporation: With electron-beam evaporation, a focused blast of electrons heats the target metal. This causes the metal to vaporize, with the particles condensing on the wafers of the semiconductor.

Filament Evaporation: Also called resistive evaporation, this process involves the heating of a filament by thermal resistance. This is typically done in a bell jar or similar device. As the filament heats up, the metal that is to be deposited melts and the filament becomes wet. The metal eventually melts completely and vaporizes, condensing on the target wafer to create the thin film layer.

Flash Evaporation: A ceramic bar that has been heated by thermal resistance is used in flash evaporation. When the bar touches a length of wire, it causes the target metal to evaporate and be deposited onto the semiconductor substrate.

Induction Evaporation: In induction evaporation, metal in a crucible is melted by radiofrequency radiation.

Denton Vacuum, LLC contributed this blog post. Visit the Denton Vacuum, LLC website to learn more about breaking thin-film technologies including PVD coating.

How Sputtering Systems Work

Sputtering is like priming a wall, but instead of paint we capture electrons. Sputtering helps engineers build more powerful processors and conductors to move energy and complete processes. Two huge applications for this process appear in computing and solar power.


Sputtering is a scientific method for applying thin layers to a surface by bombarding it with electrons and other energy particles. Sputtering is typically a slow process, and it’s best used to cover small surface areas.

Magnetron sputtering places a magnetic field around the source material that you wish to apply your layers too. The source material is electrically charged as the chamber is filled with inter gases. An alternating AC/DC current is used to magnetize the ions to the surface material, effectively bonding your layers to the surface. Some of the ions will escape the magnetic field, the rest will impact the source and deposit a fine layer of material onto the surface.

PVD Thermal Evaporation uses high temperatures to melt the materials applied to the source. A vacuum is used to create a kind of cooling chamber, condensing the vapors to form substances that can attach to the surface.

Ion beam sputtering ejects particles from the source material, and forces them to interact with electrons from a secondary source. The target is covered in neutral atoms during this process, which makes ion sputtering systems better at conducting and insulating materials and parts. You might see ion sputtering when manufacturers design a computer hard drive.

Practical Applications

We normally see sputtering during the manufacture of computer parts and solar cells.

A basic photovoltaic cell uses similar materials to what is found in a semiconductor. The process of converting sunlight into energy occurs at an atomic level, so there must be a mechanism for the conductor to actually absorb and convert the sunlight into energy.

The first solar power storage system was built in 1954, but the battery was deemed too expensive for practical usage. Today, thanks in part to plasma-enhanced chemical vapor deposition, solar power is becoming more affordable. Each cell contains a wafer-thin semiconductor that has been treated to form an electric field. The treatment leaves one side positively charged, and the other negatively charged. When light filters into the cell, the semiconductor material applied through sputtering knocks the unnecessary electrons loose. Because the conductors are attached to the cells, and have a positive and negative charge, the loose electrons get pulled into the circuit. In essence, the process of sputtering is integral to generating electricity with solar power.


This guest post was brought to you by Denton Vacuum, LLC, makers of sputtering systems for solar cells and semiconductors.