Question

15. A typical dopant concentration in a silicon device is about 1022 m3. (A) What is the ratio of the number of silicon atoms to the number of dopant atoms at this concentration? The density of silicon is 2.33 g/cm3. (B) If a manufacturing process requires that there be less than 1 uncontrolled impurity atom for every 1000 (controlled) dopant atoms, what is the allowable impurity concentration in parts per billion (1 ppb 1 impurity atom per billion silicon atoms)?

Answer 1

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