Henry Kressel & J.K.Butler
A.P.1977
"To facilitate contacts on (AlGa)As with sufficiently low resistance for CW laser operation, a ~1um thick GaAs 'cap' layer is commonly used on such heterojunction devices. The preferred method of attaching leads consists of using a soft solder such as indium because of the
possibility of damaging the device with thermocompression bonding." p.402
Semiconductor Lasers and Heterojuction LEDs
