Was this Shakespeare?

I'm looking for a sonnet I read back in high school--longer ago than I care to admit--but while I think it was one of Shakespeare's, I'm having trouble locating it.

It had something to do with death/youth/time, and may have included a description of a grave or graveyard. I think the person who had died had been young, though I'm not sure, and though I could be completely wrong about this, I think there was also some kind of implication about finding eternal youth through death.

I know that's not much to go on, but if anyone recognizes this, I'd appreciate the help.