Question

Which is considered to be a serious disadvantages of thin film capacitor, when Al2O3is used as dielectric.

(a) Additional fabrication step required

(b) It require over voltage protection

(c) Higher dielectric constant value is required

(d) All of the mentioned

The question was asked at a job interview.

Enquiry is from Active and Passive Components of IC topic in division IC Fabrication of Linear Integrated Circuits

Answer 1

The correct answer is (d) All of the mentioned. When Al2O3 (Aluminum Oxide) is used as a dielectric material in thin film capacitors, multiple serious disadvantages emerge: First, it requires additional fabrication steps to deposit and process the Al2O3 layer on the substrate. Second, it demands over voltage protection because Al2O3 has electrical properties that make it susceptible to damage under excessive voltage conditions. Third, a higher dielectric constant value is required for effective capacitance in practical applications. All these disadvantages collectively make option (d) correct, as all three issues must be addressed when designing thin film capacitors with Al2O3 as the dielectric material.