A method of forming openings to a layer of a semiconductor device comprises forming a dielectric layer over the layer of the semiconductor device, and forming a mask over the dielectric layer. The forward junction voltage and the thermal voltages have respective thermal sensitivities that act oppositely to each other so that, when the forward junction voltage is combined with the thermal voltage to produce a reference voltage, the reference voltage is substantially insensitive to temperature. The inner cannula includes a fluid inlet extending through the fluid inlet of the outer cannula and the atrial septum for placement within at least one of the left atrium and left ventricle of the heart. In the preferred embodiment, the pliable material is latex or some other rubber-like material. In a reduced-pressure environment, generating an energetic gas-cluster ion beam and subjecting the beam to increased pressure region.