Name: Aluminum oxide (AL2O3)
It is generally used in intermediate materials. This material has a good packing density and a zona pellucida in the region of 200-7000NM. Whether the process needs to add oxygen to determine by experimental analysis, increasing the substrate temperature can increase its refractive index, which is unreasonable in the coating process. When changing the situation, adjust the evaporation rate and vacuum to increase its refractive index.
Process characteristics: white granular or block, crystalline granular, etc.
Amorphous materials have high emissions of impurities, and crystalline materials are relatively small.
The refractive index is greatly affected by the degree of vaporization vacuum and the evaporation rate. If the vacuum is not good, the rate is low, and the refractive index of the film becomes lower; when the vacuum is good, the refractive index of the film is relatively increased, which is close to 1.62.
When AL2O3 evaporates, a small amount of AL molecules will be produced to cause film absorption. When appropriate O2 is added, its absorption can be avoided. However, adding oxygen should be careful not to affect its evaporation rate or change its refractive index.
Name: OS-10(TIO2+ZrO2
Process characteristics: brown granular.
When the impurity emission is large, the pre-melting is not sufficient or the vacuum degree is less than 5*10-5 Torr, the refractive index will be lower than 2.3, the help must be fully pre-melted and the evaporation vacuum degree is hoped to be greater than the above value. When evaporating this material, it is advisable to evaporate this material. Control the constant evaporation rate, materials can be added and reused, in order to reduce the amount of miscellaneous emissions, try to avoid the use of all new materials.
TI in the vapor reacts with TIO and O2 to form TIO2
It is often used to prepare anti-reflective film and SIO2 to prepare various cut-off films and filters.
Name: Germanium (Ge)
Rare metal, non-toxic and non-radioactive, mainly used in the semiconductor industry, plastic industry, infrared optical device, aerospace industry, optical fiber communication, etc. The light transmission range is 2000NM—14000NM, n=4 or even greater, melting at 937 (℃) And a kind of liquid is formed in the electron gun, and then easily evaporated at 1400 (℃). When the electron gun is used to evaporate, its density is lower than the overall bulk density, and ion-assisted plating or laser evaporation can get close to the bulk density. On germanium substrates, There are dozens of layers of 8000—12000NM bandpass filter prepared with THF4. If the temperature of the chamber is too high, the absorption will have a major change. In the range of 240–280 (℃), it will change from amorphous to crystalline. In the process, GE has a critical point.
Name: Zinc Germanium (ZnGe)
The evacuated zinc germanium has a relatively higher refractive index, N=2.6 at 500NM, and has less absorption in the visible spectral region and the 12000-14000NM region, and the evacuated zinc germanide is not as hard as its material. A tantalum boat was used to evaporate it to a 150 degree Celsius substrate to prepare SI/ZnGe and ZnGe/LaF3 films in an attempt to obtain an optical filter with a long-wavelength IR decreasing refractive index.
Name: Hafnium Oxide (HfO2)
It is vaporized with an electron gun on a substrate at 150 degrees Celsius, and the refractive index is about 2.0. It is possible to obtain a stable refractive index of 2.05-2.1 with oxygen ion-assisted plating. In the region of 8000-12000NM, HFO2 is used as the outer layer of the aluminum protective film better than SIO2
Name: Aluminum (AL)
Regardless of whether it is a decorative film or a professional film, it is commonly used to evaporate/sputter mirror films. Tungsten wires are commonly used to evaporate aluminum wires. In the ultraviolet domain, it has the best reflection performance among ordinary metals. Cu is not used in the infrared domain. , Ag, Au. Aluminum originally has a relatively high tensile stress. When the thickness is opaque, the tensile stress is reduced to small compressive stress, and the tensile stress is further reduced after steaming. The effective thickness of the film is more than 50NM.
Name: Silver (Ag)
If the vaporization speed is fast enough and the substrate temperature is not very high, silver and aluminum have good reflectivity, which is the result of a large amount of accumulation at high speed and low temperature, and this accumulation also leads to greater absorption. Silver usually does not wet tungsten. Wire, but often forms droplets with high surface tension. It can be evaporated with a high-tightness spiral tungsten wire to prevent the droplets from falling. Someone first winds the platinum wire on a V-shaped tungsten wire several times and then winds it. On the silver wire, the silver wire can wet the platinum wire but not the tungsten wire.
Name: Gold (Au)
Gold is the material with the highest reflectivity among known materials at infrared wavelengths above 1000nm. As a precious metal, it has strong chemical hardness. Due to its plasticity, it has low scratch resistance. AU can be used with tungsten or nitride. Boron boat or electron gun to evaporate (it cannot evaporate with the platinum boat, it quickly alloys with platinum). The adhesion of gold to the glass surface is low, so a layer of chromium is usually used as a colloidal layer. Oxygen ion-assisted plating can also be used to make gold The adhesion of the film is improved hundreds of times, the IAD is stopped when the opacity is reached, and the final film does not contain oxygen, and oxygen doping will reduce the reflectivity of the film.
Name: Indium—tin oxide and conductive material
Indium-tin oxide (ITO) and In3O5-SnO2 have relatively good electrical conductivity and visible light penetration. Such films have great original needs in data display screens and heat and frost-resistant devices. They can be used in buildings. Light selective window and controllable penetration window. ITO n=1.85 at500nm melting temperature is about 1450 degrees Celsius.