Chemical element symbol Si, silicon used in electronic industry should have high purity and excellent electrical and mechanical properties. Silicon is the largest and most widely used semiconductor material, and its output and consumption mark the level of a country's electronic industry.
Silicon is also one of the promising solar cell materials. The technology of making solar cells with polysilicon is mature; The research of amorphous amorphous silicon thin films has made rapid progress; Amorphous silicon solar cells began to enter the market.
chemical composition
Silicon is an elemental semiconductor. The electroactive impurities phosphorus and boron in qualified semiconductor and polysilicon should be less than 0.4ppb and 0. 1ppb respectively. When pulling the single crystal, a certain amount of electroactive impurities should be doped to obtain the required conductivity type and resistivity. Heavy metals such as copper, gold, iron and nonmetallic carbon are extremely harmful impurities, and their existence will make the performance of PN junction worse.
The carbon content in silicon is relatively high, and those below 1ppm can be considered as low-carbon single crystals. When the carbon content exceeds 3ppm, its harmful effect is obvious. Silicon has a high oxygen content. The existence of oxygen has both advantages and disadvantages. The oxygen content of Czochralski silicon single crystal is in the range of 5 ~ 40 ppm; The oxygen content of zone melting silicon single crystal can be lower than 65438±0 ppm.
Refer to the above content: Baidu Encyclopedia-Silicon Materials