What is Effective mass?

Effective mass in the explanations

• In silicon at room temperature and low doping, electron mobility is about 1400 cm²/V·s and hole mobility about 450 cm²/V·s, so electrons are about three times faster, mainly because holes have a larger effective mass.

  Which correctly compares electron and hole mobility in sili…

• The effective mass lumps this effect into a different mass and is set by the band curvature (sharper curvature means lighter).

  What is the mass introduced so that the motion of an electr…

• Treating this vacancy as a particle with positive charge and positive effective mass gives the hole, the majority carrier in p-type material.

  Which correctly describes a hole?

Questions that mention Effective mass (8)

1. Which correctly compares electron and hole mobility in silicon?
2. What is the mass introduced so that the motion of an electron in a crystal can be treated like that of a free electron in response to external forces?
3. Which correctly describes a hole?
4. What is the main reason GaAs has been used in RF amplifiers for mobile phones and similar applications?
5. When a strong field is applied to GaAs, electrons transfer to another valley with lower mobility, and negative differential resistance appears in which current decreases as the field rises. Which oscillator device uses this?
6. What is the main purpose of applying strain (stress) to a transistor's channel?
7. Why are SiGe and germanium considered or adopted instead of silicon as pMOS channel materials?
8. When a thin silicon layer is grown epitaxially on a relaxed SiGe layer with a larger lattice constant, what strain develops in the silicon?

Related terms

Mobility SiGe (silicon-germanium) GaAs (gallium arsenide) CMOS Native oxide Threshold voltage Strained silicon Acceptor Auger recombination Band gap