This paper presents a novel high speed operational amplifier using a-IGZO TFTs for a given technology, without changing device structure, processing conditions and materials. In the proposed design, a negative capacitance generator (NCG) is employed, using a-IGZO TFTs, which is connected to the output of a positive feedback operational amplifier. This technique helps to move the output pole of the amplifier to very high frequency by reducing the overall equivalent capacitance (Ceq) at the output node, as the negative capacitance is in parallel with Ceq. By using this technique, the unity gain bandwidth (GB) of the opamp is increased from 486 kHz to 1.474MHz without compromising other performance metrics, such as, gain and stability (phase margin). However power consumption is increased from 0.3mW to 0.6mW, when the simulations took place with in-house IGZO TFT models. Both NCG and the amplifier were designed with a minimum feature size of 10 um and a power supply of 10V and 15V, respectively.