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How far will metallic impurities diffuse during thermal oxidation? What is the magnitude of emitter-push effect?
The wafer is then given 1 h wet oxidation at 1000 oC. All oxide is then etched away. What is the resulting step height in silicon?
How does shadow-mask thickness affect dimensional control? What effect does the contact versus proximitymode operation have, on shadow-mask resolution?
If 340µm deep structures need to be etched and the etch bath temperature is controlled to ±1 oC, what uncertainty does this introduce in the etch time?
What is the difference in making inside versus outside spacers by anisotropic etching? How much etch non-uniformity can native oxide cause in polysilicon RIE?
Molybdenum etching in Cl2/O2 plasmas results in oxychlorides such as MoOCl4. Calculate oxide loss as a function of overetch time.
What is the deflection that corresponds to a pressure difference of 25 mtorr? What is the corresponding capacitance change?
What is the etch or polish selectivity needed in a lowk approach that uses 20 nm thick nitride etch/polishstop layers on 300 nm low-k material?
What is copper plug resistance in 0.1µm technology? What is the breakdown field requirement for low-k dielectrics?
Check with your simulator for sheet resistances, junction depths and film thicknesses. Make sure to select a proper cross section for your 1D simulation.
The wafers are 4 ohm-cm phosphorus doped. Well depth (position of pn-junction) is designed to be 5µm. What diffusion times/temperatures should be used?
Calculate the oxide thickness under the following assumptions: poly etch rate is 250 nm/min; poly thickness is 250 nm and Si:SiO2etch selectivity is 20:1.
The silicon atom density is 5 × 1022 cm-3. If dopant concentration is 10×15 cm-3 of boron, how far are the boron atoms from each other?
What is the theoretical maximum etch rate of a 200 mm diameter silicon wafers when chlorine flow is 100 sccm (standard cubic centimetres per minute)?
Aluminium wires do not tolerate current densities higher than 1 MA/cm2. What are maximum currents that can run in micrometre aluminium wiring?
The sheet resistance of a typical aluminium metallization is 0.03 ohm/sq. What is aluminium thickness?
What should the AFM-tip radius be so that resolution is tip-limited? Estimate the analytical radius of electron microprobe (EMPA).
What is the difference between the oxidation rates of boron, phosphorus and arsenic doped wafers when all have identical doping levels?
Calculate boron updiffusion for different epitaxy conditions when the buried layer doping is 1018 cm-3 and epilayer doping is 1015 cm-3.
If 20 nm of nickel reacts with overabundance of silicon, how thick a layer of NiSi will be formed? Densities: Si-2.3 g/cm3, Ni-8.9 g/cm3 , NiSi-7.2 g/cm3.
If silane (SiH4) flow in a single-wafer (150 mm) PECVD reactor is 5 sccm (cm3 /min), what is the theoretical maximum deposition rate of amorphous silicon?
If the cell area is 1µm2, with a 4 nm oxide as the capacitor dielectric, and the operating voltage is 2 V, calculate number of electrons stored in memory cell.
What is the maximum ingot size that can be pulled before the silicon yields catastrophically? What is the COP density on the wafer surface?
Electronic polysilicon is available with 0.01 ppb phosphorous concentration. What is highest ingot resistivity that can be pulled from such a starting material?
Calculate an estimate for silicon lattice constant from atomic mass and density.