Assuming this is just for fun, get hold of an old SRAM , DRAM or microprocessor chip - older the better because the silicon chip will be large.
Mill off the top of the plastic of the IC until you expose the chip and the Gold wires bonded to the chip. Remove the wires. The silicon chip is most likely a thick P-type Si, with <5 micons of "stuff" on top. Using diamond grit, polish off the "stuff" on top until the chip looks shiney.
Remove the chip from the rest of the package preserving the coppoer back contact to the chip.
Switch to colloidal silicon (really fine) polishing for making telescope mirrors and buff the exposed original top surface using as fine a felt cloth as you can. If possible use de-ionised water with the silica particles.
Now to make the worst possible schottky diode in the world, apply silver paint to the top surface and bake it using a quartz halogen bulb at max power.
You now have the worlds worst schottky diode that will leak like a Government secret, but think of the brownie points.......