Dry etching of via connections for InP power devices

Through-wafer vias fabricated in InP substrates using high-rate (>or=1 mu m min/sup -1/) dry etching in an electron cyclotron resonance (ECR) Cl/sub 2//CH/sub 4//H/sub 2//Ar discharge at 150 degrees C are reported. The low process pressure ( approximately 2 mtorr) enables creation of small diameter (30 mu m) vias using photoresist masks and the anisotropic profiles are suitable for Au plating to complete the electrical front-to-back connection.