Molybdenum coatings are essential in the thin-film transistors used in TFT-LCD screens and provide immediate control of the individual image dots (pixels). With that, a particularly sharp image quality is ensured. Other than that, Molybdenum layers are used in CIGS solar cells as back contacts.
Production of molybdenum thin films
The magnetron sputtering method is based on the vaporisation of tiny metal particles from the sputtering targets which are subsequently deposited as a thin film on the glass substrate. This is a fast and economical coating process. Of course, all materials must meet the highest quality criteria.
Planar molybdenum targets
For more than 20 years, Plansee materials have been applied as thin films in TFT displays.
Plansee offers both single and multi-piece planar & rotary targets which will be bonded in-house. Besides, Plansee produces sputtering targets for all commonly used systems as well as to individual customer needs.
The key features for the films are:
An exceptional level of electrical conductivity and minimised particle formation during the PVD process. This is due to the fact that metallic and gaseous impurities in the sputtering target are reproduced almost 1:1 in the sputtered functional layer and cause particle formation during the PVD process. This is known as the arcing effect.
Plansee guarantees a purity of at least 99.97% for their molybdenum targets. On average the purity of Plansee's targets reaches even an unbeatable 99.99%. Moreover, the typical oxygen content is as low as 6 ppm.
Like this, Plansee helps to ensure that every pixel in the TFT-LCD display can be controlled precisely and that the CIGS back contact functions correctly.
Due to their special forming processes, Plansee's molybdenum sputtering targets reach a density of almost 100%, leading to a faster process due to increased sputtering speeds. The higher the molybdenum target density, the higher the conductivity of the created layer.