You have to have the trademark approved, and they don't really care how big your company is, they will not approve a trademark for the word silicon. See: clothi

You have to have the trademark approved, and they don't really care how big your company is, they will not approve a trademark for the word silicon. See: clothing brand Supreme's attempt to trademark their Supreme logo on a red background. If apple combines the word with a unique logo or combines it with some other word, they can get the trademark, but you can't get it for the word silicon by itself.