What is the work function of polysilicon?

What is the work function of polysilicon?

What is the work function of polysilicon?

Polysilicons were used as their work function matched with the Si substrate (which results in the low threshold voltage of MOSFET). Metal gates were re-introduced at the time when SiO2 dielectrics are being replaced by high-k dielectrics like Hafnium oxide as gate oxide in the mainstream CMOS technology.

Why do we use polysilicon instead of metal?

The source and drain region is created using ion-implantation method, which is a very high temperature annealing process. If metal is used as gate then it would melt. The melting point of polysilicon is higher, this is also one of the reason for choosing polysilicon over metal.

What metal is used in MOSFET?

8.2. A MOSFET sensor comprises three layers – a silicon semiconductor, a silicon oxide insulator, and a catalytic metal (usually palladium, platinum, iridium, or rhodium), also called the gate.

Why is polysilicon a gate material?

Thus, poly-crystalline silicon (polysilicon) became the modern gate material because it is the same chemical composition as the silicon channel beneath the gate oxide. In inversion, the work-function difference is close to zero, making the threshold voltage lower and ensuring the transistor can be turned on.

What is the difference between silicon and polysilicon?

In context|chemistry|lang=en terms the difference between silicon and polysilicon. is that silicon is (chemistry) a nonmetallic element (symbol si) with an atomic number of 14 and atomic weight of 280855 while polysilicon is (chemistry) containing many silicon atoms, especially when linked into chains or networks.

Why is polysilicon used for gate?

What is the difference between polysilicon and silicon?

Why metal is used in MOSFET?

Copper and aluminum are the metals used to make MOSFET interconnects. From 1970 to 2000, aluminum was the dominant interconnect metal for the following reasons: Copper creates a trap energy level in silicon that makes charge carriers recombine faster, which is detrimental to device performance.

What is polysilicon resistor?

Practically, the polysilicon resistor is a material which is widely used throughout the semiconductor industry. Generally, the doped polysilicon is used as a precise analog resistor element [1-3].

Where is polysilicon found?

China is a leader in the manufacture of polysilicon — the basic material that goes into making solar panels. China has cracked the code for how to make high quality, cheap polysilicon.