Hi Cindy,

I think Platinum when deposited over Silicon forms Platinium Silicide
which has important consequences when u make a device. Platinum
and Silicon  atoms diffuse to form a Pt silicide phase(PtSix). Due to weak
bonding  with the silicide phase,  it 'could be' that the platinum peels
off.
But I haven't observed any peeling other than the formation of silicides.

Here are some reference papers which might be helpful

The interaction between platinum films and silicon substrates: Effects of
substrate bias during sputtering deposition
    J. Shi, D. Kojima, and M. Hashimoto
Journal of Applied Physics Vol 88(3) pp. 1679-1683. August 1, 2000

Pt2Si and PtSi formation with high-purity Pt thin films
    C. Canali, C. Catellani, M. Prudenziati, W. H. Wadlin, and C. A. Evans,
Jr.

   Applied Physics Letters Vol 31(1) pp. 43-45. July 1, 1977

Growth rates for Pt2Si and PtSi formation under UHV and controlled impurity
atmospheres
    C. A. Crider and J. M. Poate

   Applied Physics Letters Vol 36(6) pp. 417-419. March 15, 1980


greetings,

Rajesh