Possible Clues:

• Non-metallic element, symbol Si
• Chip ingredient
• Sounds as if stupid Cornelius gets to the valley for technology (7)
• Element that's foolish, we hear, to study
• California's ___ Valley / Goofy? (... letters 2 and 4)
• Semiconductor element
• Element in soil (not oxygen) I study
• Senseless-sounding scam involving semiconductor
• More than a quarter of the earth's crust
• Electronic circuit element