1 micro meter = [tex] 10^{-6} meters[/tex]
1 μm ^2 = 1 μm*1μm = [tex] 10^{-6} *10^{-6} = 10^{-12} [/tex] meters
1.5 μm^2 = 1.5 * [tex] 10^{-12} [/tex] meters
μm^2 is a unit for surface. First you want to convert μm to meters which is unit for length and if you multiply units for length you get unit for surface.
