One of the most critical requirements for semiconductors in space is meeting the on-orbit radiation requirements of the satellite mission. Radiation requirements for most satellite missions are classified into two main criteria: total ionizing dose (TID) effects due to absorbed gamma radiation and single event effects (SEE) due to heavy ions. The level of radiation performance is based on the mission orbit, timeline, and shielding. Once the requirements are established for the mission, our customers typically look to Microsemi to prove that our space-qualified device can meet those limits.

SEE performance does not typically change from lot to lot or wafer to wafer once the design is frozen. This equates to costly and sometimes lengthy upfront evaluation as the device is being released, but means future devices with the same design can be built without additional monitoring once the SEE performance is established.

The opposite can be true when you look at TID performance, as some process technologies will vary lot-to-lot and wafer to wafer. This creates the need to perform TID performance monitoring in production to guarantee a device will meet its target TID level (30 krad, 50 krad, 100 krad, and so on). Implementing TID monitoring does not drastically affect the lead-time for CMOS devices, as they aren’t sensitive to low dose rate (LDR) and so can be quickly verified at high dose rate (50 rad/sec–100 rad/sec).

Because bipolar devices are known to exhibit sensitivity to dose rate, they are commonly called enhanced low dose rate sensitive (ELDRS) devices. Therefore, many of our space customers require bipolar devices to be qualified at LDR on a wafer-by-wafer basis. For devices sensitive to LDR, it can take upwards of five months to collect 100 krad data on a particular wafer or lot. If the wafer or lot fails, the process has to be re-started, adding another 5 months to have qualified devices.

To avoid these long lead times for customers, Microsemi has built up pre-qualified wafers of the 2N2222A* and the 2N2907A* (2N3700* and 2N2369A* complete 2H18). With pre-radiation tested wafers and over 600K burn-in sockets, Microsemi maintains significant capacity to meet the needs of the largest programs.

Devices are orderable under standard JANS, JANTXV, and JANTX part numbers with LDR data request on the purchase order.

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Tags: Aerospace, Pre-Qualified Wafers, Satellite Missions, SEE, Single Event Effects, Space, TID, Total Ionizing Dose