Why is silicon germanium used?

Why is silicon germanium used?

Silicon–germanium is an important material that is used for the fabrication of SiGe heterojunction bipolar transistors and strained Si metal–oxide–semiconductor (MOS) transistors for advanced complementary metal—oxide–semiconductor (CMOS) and BiCMOS (bipolar CMOS) technologies.

Why is the silicon mostly chosen when compared to the germanium?

The variation of Collector cut off current with temperature is less in Silicon compared to Germanium. However, Silicon crystals are not easily damaged by excess heat. Peak Inverse Voltage ratings of Silicon diodes are greater than Germanium diodes. Si is less expensive due to the greater abundance of element.

Why is germanium used as a semiconductor?

Silicon and germanium are used here effectively because they have 4 valence electrons in their outermost shell which gives them the ability to gain or lose electrons equally at the same time.

Is germanium still used?

Today, germanium is mined primarily from sphalerite (the primary ore of zinc), though germanium is also recovered commercially from silver, lead, and copper ores. Elemental germanium is used as a semiconductor in transistors and various other electronic devices.

What is difference between silicon and germanium?

Silicon is a chemical element with atomic number 14 and chemical symbol Si while germanium is a chemical element with atomic number 32 and chemical symbol is Ge. The key difference between silicon and germanium is that Germanium has d electrons, but Silicon does not have any d electrons.

Why is silicon used instead of germanium in semiconductors?

Consequently, the modern trend is to use silicon in semiconductor devices. At room temperature, Silicon crystal has fewer free electrons than Germanium crystal. This implies that silicon will have much smaller Collector cut off current than Germanium.

When did they start using germanium in transistors?

In the years following, germanium-containing transistors found their way into telephone switching equipment, military computers, hearing aids and portable radios. Things began to change after 1954, however, when Gordon Teal of Texas Instruments invented a silicon transistor.

What is the maximum temperature that germanium can be used for?

The structure of germanium will be destroyed at a temperature of approximately 100°C. The maximum normal working temperature of germanium is 70°C but silicon can be operated upto 150°C. Therefore, silicon devices are not easily damaged by excess heat. (iv) Higher PIVrating.

What kind of technology can germanium be used for?

Germanium is a rare, silver-colored semiconductor metal that is used in infrared technology, fiber optic cables, and solar cells. Technically, germanium is classified as a metalloid or semi-metal. One of a group of elements that possess properties of both metals and non-metals. In its metallic form, germanium is silver in color, hard, and brittle.