Is the RHF350A a silicon-germanium (SiGe) opamp?

[ELivi.1]

Hello,

I'm searching for a space grade/rad hard, low noise (<5nV/rtHz), high bandwidth opamp (>100 MHz) for cryogenic operation. SiGe opamps are generally known to perform favorably at cryogenic temperatures. At first glance the RHF350A has good specs for my application but it's not clear to me if it's a SiGe device or not.