Answer / madhu

Latch-up is a condition in which the parasitic components
give rise to the Establishment of low resistance conducting
path between VDD and VSS with Disastrous results.

Answer / coolmoon

Latch up effect can be minimized by 1.putting the isolation
between pmos and nmos regions.
2. changing the dopping concentrations thus reducing the
gain of pnpn device.

SOI (silicon on insulator)doesnt have any latch up problem.

because of latch up effect there is the short between power
lines and the continuous current flows through the device
till the power down. This results into malfunctioning of
the device, resulting into its damage. This latch problem
is observed in case of two transistors arranged side by
side forming pnpn/npnp structure. (structure like SCR or
thyristor).

Answer / abhishek

Latch up refers to the creation of a low resistance path between power and ground. This is essentially created due to parasitic bipolars getting active.

To minimize chances of latch up:

1. Use of guard rings - they are nothing but a N+ or P+ ring around the device which is suitably biased to power/ground respectively. How they help is that if by chance there are carriers like electrons in the substrate, they are trapped/attracted by the respective wells.

2. Keeping the substrate traps close to the devices This reduces bulk resistance and helps minimize risk of LU

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