accurate resistor

hi

Implementing all elements of circuits on chip is common these days. I know implementing resistors on chip makes almost 20% tolerance in resistor values. on the other hand, in some case, we need accurate resistors. I want to know about methods that employed for implementing accurate resistor ?

Thank you.

precision thin film resistor are accurate from 0.1% to 1% . Do you ask for manufacturing process?

-Ts

Hi

Thank you for your attention

Yes, I want to know how much extra chip area or cost we need for employing this kind of inductor? if it is possible discribe it's manufactring proccess or introduce one refference about this subject.

best regards.
M.Forouzanfar