From the mints website--
http://www.mint.ca/store/mint/learn/1-cent-5300004#.UU9A8Rm9bPY1997 to present*
Composition: 98.4% zinc, 1.6% copper plating
Weight (g): 2.25
Diameter (mm): 19.05
Thickness (mm): 1.45
2000 to date*
Composition: 94% steel, 1.5% nickel, 4.5% copper plating
Weight (g): 2.35
Diameter (mm): 19.05
Thickness (mm): 1.45
*Note: Since 2000, the 1-cent coin can be produced using either the copper-plated steel or copper-plated zinc compositions.
FYI Jarden made the zinc planchets for Canada same as for the US.
So 1997-1999 are zinc
1999-2006 had a P mint mark for the steel ones.
2006-2012 Both zinc and steel have RMC mint mark.
Also there is a rare 2006 P - Non magnetic worth a $100+
In 2006, for some unknown reason, non-magnetic planchets were used to produce coins with a P below the effigy of the queen.