Consider an MOS capacitor with a p+ poly-Si gate (EF = EV) and a p-type substrate with NA = 10^16 cm−3, tox = 15 nm, ni = 10^10 cm−3, T = 300 K, Es = 11.7, Eox = 3.9, EG(poly-Si) = EG(Si) = 1.12 eV. Determine the flatband voltage VFB and the normalized flatband capacitance CFB/Cox.
Consider an MOS capacitor with a p+ poly-Si gate (EF = EV) and a p-type substrate...
Problem 5: The gate capacitance vs. gate voltage characteristic of a p+ poly-Si gated MOS capacitor of area 1x10"cm', is as shown: Assume Esi = 11.9, Eox-39,E,-8.85 × 10-14 F/on, and nl = 1.5 x 1010 cm3 Co [Farads] 3.45x1011 >Va [Volts] 1.0 0.3 (a) Is the semiconductor (silicon) substrate doped n-type or p-type? Explain briefly. (b) Is the measurement frequency low or high? Explain briefly. (c) What is the thickness of the gate oxide (SiO2), xo? (d) Estimate the...
Problem l: The capacitance vs. gate voltage characteristic of a simple MOS capacitor of area 100 μιηχ 1 00pm is as shown: Assume Esi-1 1.9, Eox-3.9, Eo-8.85 >< 10-14 F/cm, and ni-1.5x 1010cm3 C (pF) 70 ECV) 0.25 a) What is the thickness of the gate oxide (Sio2)? b) Does the capacitor have a metal gate or poly-Si gate? Why? c) Is the substrate n-type or p-type? How do you know? d) Estimate the values of VFB and VrH. e)...
Section B (total 60 marks for section B) B1 a) An MOS capacitor has a p-type semiconductor substrate doped with an impurity concentration of 1018 cm3. Assume a poly-Si material is used for the gate. Draw a diagram of the capacitor structure showing material types and an energy band diagram it is in thermal equilibrium. (10 marks) b) Given an MOS capacitor with a p-type semiconductor substrate and poly-Si material as gate (in part a), what is the meaning of...
Problem 3 (25 points) Consider a MOS capacitor with p polysilicon gate and p-type silicon substrate with NA 1016 cm3. Ef- Ev in the polysilicon gate. Assume the following parameters: I200A, , 1.5x10° cm*,E, -3.9x8.854x104FIcm ox a) (5 points) Calculate the metal-semiconductor work function difference. b) (5 points) Calculate the surface potential at the threshold inversion. c) (5 points) Calculate the depletion width (in μm) at the threshold inversion. d) (5 points) Calculate the flat band voltage. e) (5 points)...
Problem 3: Consider a MOS capacitor maintained at T= 300K with the following characteristics: Assume s 11.9, ox 3.9, 8.85x 10-1 F/cm, and n 1.5 x 1010cm3 Gate material is n poly-silicon Total negative oxide charge of 5x 1011q C/cm . Substrate is n-type Si, with doping concentration 1 x1016 cm-3 Oxide thickness 5 nmm The electron affinity for Si is 4.03eV? e) What is the flat capacitance? f) What is the depletion region width? g) What is the potential...
Problem 1. An n-channel MOS transistor is fabricated with the following specifications: Substrate is a p-type silicon with doping concentration NA=2x1015 cm-3 . The SiO2 gate thickness is 200 Å. Effective interface charges Qi=6.5x10-9 col/cm2. Work function difference between gate conductor and silicon substrate qфms=-0.95 eV. Calculate the following: a. Maximum depletion width, with respect to ground b. Gate capacitance per unit area, Ci c. Flat-band voltage, VFB d. Threshold voltage, VT.
Assignment-2) Consider a MOS structure made out of a W gate (WM = 4.54 eV), a 4.5 nm SiO2 insulator, and a p-type Si substrate with NA = 6x1017 cm-3. Estimate the electric field in the oxide and the surface potential at zero bias.
Consider a modern PMOS capacitor with an Pt gate[1](ΦM= 5.1 eV) and n-type silicon substrate (ND= 1018cm-3). (a) The desired oxide capacitance is 2.5 µF/cm2. Calculate the SiO2thickness and the HfO2thickness that can enable this capacitance. If the thickness of a monolayer of SiO2is 3.5 Å, how many monolayers is that? What is the advantage of using HfO2? (b) Calculate the substrate work function and the flatband voltage of the capacitor. Now qualitatively (but carefully) sketch the band diagrams under...
Assignment-2) Consider a MOS structure made out of a W gate (WM = 4.54 eV), a 4.5 nm SiO2 insulator, and a p-type Si substrate with NA = 6x1017 cm-3. Estimate the electric field in the oxide and the surface potential at zero bias.
Problem3: Consider a MOS capacitor maintained at T 300K with the following characteristics: Assume Esi 1.9,x 3.9,8.85 x 10-14 F/cm, and n 1.5 x 1010cm3 . Gate material is n+ poly-silicon . Total negative oxide charge of 5x 1011q C/cnm2 . Substrate is n-type Si, with doping concentration 1x1016 cm3 Oxide thickness 5 nm . The electron affinity for Si is 4.03eV? a) Draw the band diagram at equilibrium. b) From part (a). What is the substrate (bulk) condition at...