Testability and yield of MMICs

Summary form only given. An approach to MMIC (monolithic microwave integrated circuit) yield measurement involving on-wafer functional testing was discussed. On-wafer RF testing, combined with minimum DC testing, provides the necessary testing of individual chips with minimum costs. The on-wafer tests used to screen MMICs for yield current include measurements of output power, complex gain, return loss, noise, and spurious output. To provide effective on-wafer screening of MMICs, testability must be included as part of the design. The design issues that influence on-wafer testability include pad placement, stability, number of connections, and thermal resistance. The testing required to identify good die may range from full functional testing of every specification to simple DC screening. The required level of testing is usually related to the performance requirements of the chip and the design margins.<>