DRAM memory in computers works as a capacitor. Nowadays, the capacitance of this capacitor is reduced down to around 30 fF. The area of such capacitors is around 0.7 square micrometers. High dielectric constant dielectrics are used, with ε values up to 20. What is the thickness of such a capacitor? Please give the answer in NANOMETERS including "nm" (i.e. 36 nm). Please, don't use a chat GPT. He provided the incorrect answer.