We propose and evaluate by simulation a novel membrane electro-absorption modulator heterogeneously integrated on silicon. The device is based on the electronconcentration dependent absorption of highly-doped n-InGaAs. It is predicted that the modulator can be operated over a wavelength range of more than 100 nm and provides a static extinction ratio of 7.2 dB, an insertion loss of 5.4 dB, a modulation speed above 50 Gbit/s and a power consumption of 53 fJ/bit. The modulator has a small footprint of 0.4 × 80 um2 (excluding contact pads) and operates on a CMOS compatible 1.5 V voltage swing.