Introduction to ceramic targets

Ceramic targets are relatively brittle targets. Generally, ceramic targets are bound to back plates for use. Back plates can not only support ceramic targets in the sputtering process, but also play a role in heat transfer during the sputtering process. There are many types of ceramic targets with a wide range of applications, mainly used in microelectronics, display, storage and other fields. As the basic material for the development of non-metallic film industry, ceramic targets have achieved unprecedented development

Types and applications of ceramic targets

According to application, it can be divided into semiconductor related ceramic target, display ceramic target, magnetic recording ceramic target, optical recording ceramic target, superconducting ceramic target, giant magnetoresistance ceramic target, etc

Semiconductor related ceramic targets (HfO, SiO, Si3N4, MoSi, TaSi, WSi, TiSi, PLZT, ITO) are mainly used in grid dielectric film, tossing film, diffusion barrier film, capacitor insulation film, transparent conductive film;

Display ceramic targets ZnS-Mn, ZnS-Tb, ZnS-Sm, CaS-Eu, SrS-Ce, Si3N4, MgO, mainly used in electroluminescent thin film luminescent layer and electroluminescent thin film insulating layer

Magnetic recording ceramic target Si3N4, mainly used for magnetic head and magneto-optical disk (MO) protection;

Optical recording ceramic rake material Si3N4, mainly used for optical disc protective film;

Superconducting ceramic targets YbaCuO and BiSrCaCuO are mainly used in superconducting thin films;

Giant magnetoresistance ceramic target, mainly used in thin film solar cell window;

Other application targets InO, LiNbO, BaTiO, PZT ZnO, mainly used in solar cells and piezoelectric films

According to chemical composition, it can be divided into oxide ceramic target, silicide ceramic target, nitride ceramic target, fluoride ceramic target and sulfide ceramic target. Among them, ITO ceramic target has been widely produced and applied in China. Ceramic target for high dielectric insulating film and giant magnetoresistance ceramic target have broad application prospects

For example, oxide ceramic sputtering target is the most common target among advanced ceramic sputtering targets. Oxide ceramics can be made by sintering at high temperature. One or more oxides are the main components, while other secondary oxides are additives. They are divided into simple oxide ceramics and complex oxide ceramics. Common sputtering targets of this type include aluminum oxide (Al2O3), magnesium oxide (MgO), beryllium oxide (BeO), zirconia (ZrO2), etc. Most oxide ceramics have high melting point, excellent insulation, heat resistance, antioxidant and corrosion resistance. Therefore, they can be exposed to high temperature and oxidation environment for a long time, and are worthy of wide application in the engineering field.

Preparation process of ceramic target

Drying: place the starting raw material in the oven for 3~6 hours before weighing, and the drying temperature is 100~120

Ingredients: weigh the dried raw materials according to the corresponding stoichiometric ratio;

Ball milling: mix the weighed raw materials in a certain way, and the mixing time is 4~12 hours to make a uniform slurry;

Drying: drying the prepared uniform slurry;

Calcination: sift the dried powder and gently press it into a block and place it in a muffle furnace, calcine it at 800~950 ℃ for 4~8 hours

Ball milling: grind the calcined powder into fine powder, ball milling and drying again to obtain ceramic powder;

Billet making: press the ceramic powder made into samples with a diameter of 5~20mm and a thickness of 0.5~1.2mm by hand with a steel mold, put the samples into a cold isostatic press, apply a pressure of 200~350MPa, and hold the pressure for 60~180s to make the ceramic body;

Sintering: place the ceramic body made in a muffle furnace and sinter it at 1100~1200 ℃

Cooling: natural cooling to room temperature, that is, a certain ceramic target is prepared

Note: The temperature and time provided are only used as reference data

Characteristic requirements of ceramic target

Purity: The purity of the ceramic target has a great influence on the performance of the sputtered film. The higher the purity, the better the uniformity of the sputtered film and the consistency of the quality of the batch products

Density: In order to reduce the porosity of the ceramic target and improve the film performance, the sputtering ceramic target is required to have high density

Composition and structure uniformity: In order to ensure the uniformity of the sputtered film, especially in the complex large-area coating application, the target composition and structure uniformity must be good