Home 2 Return by January 29th, 22.00 o’clock Into Return box 2 in MyCourses. PowerPoint presentation is a very welcome form for submitting the exercises.

Q1: Thin film vs. epitaxy Explore how thin film deposition and epitaxy are related. What are the similarities ? What are the differences ? Materialswise ? Equipmentwise ? Applicationwise ? Fundamentally ?

Q2: Resistivity and resistor a) What are the resistivities of the two tantalum films of Fig. 5.1 ? Why are they different ? b) Resistor design: choose one of the tantalum films and make a 10 kOhm resistor out of it using a 3 µm linewidth process. How long is the resistor ?

Q3: Polysilicon resistor Circuit designer has reserved 100x100 µm area for a resistor. If the resistor is made of polysilicon, and minimum linewidth is 3 µm, what are the largest and the smallest resistance values that can be obtained ?

Q4: Silicon wafers Silicon wafers were delivered to you during the lecture. Study (from Introduction to Microfabrication and other sources) properties of these wafers: Measure the thickness of your wafer ! Assuming the wafer is n++ with arsenic dopant, how many grams of arsenic is there in the wafer ? n++ ? Read the textbook! If USA from New York to Los Angeles was polished to same finish as the silicon wafer, how high would the highest mountains be ? Before the silicon wafer was taken out of the box, how many particles and what size were there on the wafer ? What was the problem with the wafer, i.e. why did Okmetic donate it to teaching and not sell to a customer ? You should list at least 5 possible reasons.

Q5: PECVD deposition If silane (SiH4) flow in a single wafer PECVD reactor is 5 cm3/min (also known as sccm), under standard temperature and pressure, what is the theoretical maximum deposition rate of amorphous silicon on a 150 mm wafer ? Calculate via the number of atoms: gas molecules flow into reactor, and solid film grows on wafer. In the end, explain which processes reduce the deposition rate from the theoretical maximum, and give a guess of a practical deposition rate.