A novel etching technology with reactive ion etching system for GaAs via-hole etching applications

A via-hole dry etching technique has been studied with manipulating RF power and gas pressures in a reactive ion etching system. These parameters were optimized into a two-step recipe. With the recipe, a sloped and smooth profile can be obtained for monolithic microwave integrated circuits and power FET applications. With the two-step etching recipe, greater than 25:1 selectivity between GaAs/photoresist and less than 10% etching deviation were obtained. Furthermore, the slope angle from the horizontal surface is less than 80degrees.