ABSTRACT
CMOS compatible infrared waveguide Si photodiodes are made responsive from 1100 to 1750 nm by Si(+) implantation and annealing. This article compares diodes fabricated using two annealing temperatures, 300 and 475 degrees C. 0.25-mm-long diodes annealed to 300 degrees C have a response to 1539 nm radiation of 0.1 A W-(-1) at a reverse bias of 5 V and 1.2 A W(-1) at 20 V. 3-mm-long diodes processed to 475 degrees C exhibited two states, L1 and L2, with photo responses of 0.3 +/-0.1 A W(-1) at 5 V and 0.7 +/-0.2 A W(-1) at 20 V for the L1 state and 0.5 +/-0.2 A W(-1) at 5 V and 4 to 20 A W(-1)-1 at 20 V for the L2 state. The diodes can be switched between L1 and L2. The bandwidths vary from 10 to 20 GHz. These diodes will generate electrical power from the incident radiation with efficiencies from 4 to 10 %.
ABSTRACT
A contoured elastic-membrane microvalve is presented that enables integrated microfluidic processing at the network level. This method takes advantage of two ideas to improve performance: flexible elastic membranes (which enable high-performance shutoff and reduced footprint), and three-dimensionally contoured valve geometries (which reduce dead volume, improve fluidic priming, and reduce susceptibility to cavitation at high fluid velocities). We describe the use of laser-induced etching for microfluidic manifold fabrication, discuss the nonlinear load-deflection behavior of elastic membranes that can occur below 30 psi, and present flow-rate data for microvalves under inlet pressures of 0-20 psi with zero applied membrane pressure. Valve-closure data for inlet pressures of 0-30 psi are presented for fully assembled microvalve structures. The microvalve structures under test were capable of turning off flows of > 20 microL/s. These flow rates were shown to be limited by inlet and outlet flow resistances and not by the valve structure itself, so that higher maximum flow rate capabilities should be readily achieved.
