With the rapid development and increasingly expanding application fields of RF/microwave devices, various device integration processes based on semiconductor monolithic integration technology have been developing. A GaAs compound substrate with AlGaAs-InGaAs is studied. The succinic acid wet etching process has less influence on the electrical performance of the device. The depleted and enhanced pseudomorphic high-electron-mobility transistor (pHEMT) devices are integrated into the same chip semiconductor process technology. The results show that the Y-gate of enhanced transistor has a linewidth of 0.25 m and an opening voltage of 0.3 V; the gate of depleted transistor has a linewidth of 0.5 m and an opening voltage of -0.8 V. The gate voltage distribution from negative to positive on the same chip is realized, and a broader design platform for designers is provided. This integration technology can be applied to fields such as low noise amplifiers, linear antenna switches, filters, and power control devices.