Commercially available p+ nn+ passivated implanted planar silicon detectors have been shown to be very performing for standard RBS-analysis with He-4 beams. Lifetimes are found to range up till > 10(9) particles. The end of lifetime occurs concurrent with internal breakdown of the detector. Inverted n+ np+ detectors where the junction is located well outside the damage region, are expected to be less sensitive to the radiation damage and to have a higher lifetime. In the present paper the characteristics for heavy-ion detection of both types of detector are investigated and discussed upon.