what are the possible ways to improve slew rate of an operational amplifier in CMOS technology?
What defines the SlewRate? dv/dt = I/C
Many opamps have an internally-compensated "BIG CAP" approach. Examine the schematic of the Fairchild UA709, find its several Rs and Cs that provide the stabilization, and understand that.
Then ask yourself once again ----- what defines the SlewRate?
Its still working with Q = C * V, differentiated and assuming C is constant, to arrive at dV/dT = I/C.