ALD HfO2 and Al2O3 as MIM Capacitor Dielectric for GaAs HBT Technology

Due to the increasing demand for capacity and due to the increasing complexity and functionality of devices and designs, the die size in semiconductor wafer manufacturing must be reduced. One of the methods to reduce the design and die size is to increase the capacitance density and/or reducing the area of the metal-insulator-metal (MIM) capacitor, which is a key passive component in GaAs applications. Excluding the areas of the bond pad and scribe streets, MIM capacitors could consume up to 35% of the die area in many GaAs circuit designs (1,2). Increasing the capacitance density of the MIM capacitors in these designs will allow capacitor area reduction, which in turn will result in die size reduction. Furthermore, higher capacitance density will allow the integration of off-chip capacitors on the chip itself, thereby reducing the bill-of-materials in a multi-chip module.