Abstract: A semiconductor structure includes a substrate, and an active device and a passive device over the substrate. The active device is disposed in a first region of the substrate, and the passive device is disposed in a second region of the substrate. The semiconductor structure further includes a shielding structure and a passivation layer. The shielding structure includes a barrier layer and a ceiling layer. The barrier layer is on the passive device and the active device, and the ceiling layer is on the barrier layer. The passivation layer is under the barrier layer and covers a top surface of the passive device. An air cavity is defined by sidewalls of the barrier layer, a bottom surface of the ceiling layer, and the substrate.

Abstract: A semiconductor structure includes a substrate, and an active device and a passive device over the substrate. The active device is disposed in a first region of the substrate, and the passive device is disposed in a second region of the substrate. The semiconductor structure further includes a shielding structure and a passivation layer. The shielding structure includes a barrier layer and a ceiling layer. The barrier layer is on the passive device and the active device, and the ceiling layer is on the barrier layer. The passivation layer is under the barrier layer and covers a top surface of the passive device. An air cavity is defined by sidewalls of the barrier layer, a bottom surface of the ceiling layer, and the substrate.

Abstract: A semiconductor structure includes a substrate, a passive device and an active device over the substrate. The active device is formed in the first region of the substrate, and the passive device is formed in the second region of the substrate. The semiconductor structure further includes a passivation layer that covers the top surface of the passive device. The passivation layer has an opening that exposes the active device.

Abstract: A semiconductor structure includes a substrate, a passive device and an active device over the substrate. The active device is formed in the first region of the substrate, and the passive device is formed in the second region of the substrate. The semiconductor structure further includes a passivation layer that covers the top surface of the passive device. The passivation layer has an opening that exposes the active device.

Abstract: A monolithic integration of enhancement mode (E-mode) and depletion mode (D-mode) field effect transistors (FETs) comprises a compound semiconductor substrate overlaid by an epitaxial structure overlaid by source and drain electrodes. The epitaxial structure includes from bottom to top sequentially a buffer layer, a channel layer, a Schottky barrier layer, a first etch stop layer, and a first cap layer. The respective first gate metal layers of the D-mode and E-mode FET are in contact with the first etch stop layer. The D-mode and E-mode gate-sinking regions are beneath the respective first gate metal layers of the D-mode and E-mode gate electrode at least within the first etch stop layer. The first gate metal layer material of the D-mode is the same as that of the E-mode, where the first gate metal layer thickness of the E-mode is greater than that of the D-mode.

Abstract: A gate-sinking pseudomorphic high electron mobility transistor comprises a compound semiconductor substrate overlaid with an epitaxial structure which includes sequentially a buffer layer, a channel layer, a Schottky layer, and a first cap layer. The Schottky layer comprises from bottom to top at least two stacked regions of semiconductor material. Each of the two adjacent stacked regions differs in material from the other and provides a stacked region contact interface therebetween. In any two adjacent stacked regions of the Schottky layer, one stacked region composed of AlGaAs-based semiconductor material alternates with the other stacked region composed of InGaP-based semiconductor material. A gate-sinking region is beneath the first gate metal layer of the gate electrode, and the bottom boundary of the gate-sinking region is located at the one of the at least one stacked region contact interface of the Schottky layer.

Abstract: A monolithic integrated circuit device formed in a multi-layer structure comprises a low-pinch-off-voltage pHEMT and a high-pinch-off-voltage pHEMT. A Schottky layer in the multi-layer structure contains at least three stacked regions of semiconductor material, wherein each of the two adjacent stacked regions differs in material and provides a stacked region contact interface therebetween. The gate-sinking pHEMTs each includes a gate contact, a first gate metal layer, a gate-sinking region, and a gate-sinking bottom boundary. The first gate metal layers are in contact with the topmost stacked region of the Schottky layer. The gate-sinking regions are beneath the first gate metal layers. The gate-sinking bottom boundary of the high-pinch-off-voltage pHEMT, which is closer to the semiconductor substrate than the gate-sinking bottom boundary of the low-pinch-off-voltage pHEMT, locates within 10 ? above or below one of the stacked region contact interfaces of the Schottky layer.

Abstract: A monolithic integrated circuit device formed in a multi-layer structure comprises a low-pinch-off-voltage pHEMT and a high-pinch-off-voltage pHEMT. A Schottky layer in the multi-layer structure contains at least three stacked regions of semiconductor material, wherein each of the two adjacent stacked regions differs in material and provides a stacked region contact interface therebetween. The gate-sinking pHEMTs each includes a gate contact, a first gate metal layer, a gate-sinking region, and a gate-sinking bottom boundary. The first gate metal layers are in contact with the topmost stacked region of the Schottky layer. The gate-sinking regions are beneath the first gate metal layers. The gate-sinking bottom boundary of the high-pinch-off-voltage pHEMT, which is closer to the semiconductor substrate than the gate-sinking bottom boundary of the low-pinch-off-voltage pHEMT, locates within 10 ? above or below one of the stacked region contact interfaces of the Schottky layer.

Abstract: A gate-sinking pseudomorphic high electron mobility transistor comprises a compound semiconductor substrate overlaid with an epitaxial structure which includes sequentially a buffer layer, a channel layer, a Schottky layer, and a first cap layer. The Schottky layer comprises from bottom to top at least two stacked regions of semiconductor material. Each of the two adjacent stacked regions differs in material from the other and provides a stacked region contact interface therebetween. In any two adjacent stacked regions of the Schottky layer, one stacked region composed of AlGaAs-based semiconductor material alternates with the other stacked region composed of InGaP-based semiconductor material. A gate-sinking region is beneath the first gate metal layer of the gate electrode, and the bottom boundary of the gate-sinking region is located at the one of the at least one stacked region contact interface of the Schottky layer.

Abstract: A monolithic integration of enhancement mode (E-mode) and depletion mode (D-mode) field effect transistors (FETs) comprises a compound semiconductor substrate overlaid by an epitaxial structure overlaid by source and drain electrodes. The epitaxial structure includes from bottom to top sequentially a buffer layer, a channel layer, a Schottky barrier layer, a first etch stop layer, and a first cap layer. The respective first gate metal layers of the D-mode and E-mode FET are in contact with the first etch stop layer. The D-mode and E-mode gate-sinking regions are beneath the respective first gate metal layers of the D-mode and E-mode gate electrode at least within the first etch stop layer. The first gate metal layer material of the D-mode is the same as that of the E-mode, where the first gate metal layer thickness of the E-mode is greater than that of the D-mode.

Abstract: A monolithic integration of enhancement mode (E-mode) and depletion mode (D-mode) field effect transistors (FETs) comprises a compound semiconductor substrate overlaid by an epitaxial structure overlaid by source and drain electrodes. The epitaxial structure includes from bottom to top sequentially a buffer layer, a channel layer, a Schottky barrier layer, a first etch stop layer, and a first cap layer. The respective first gate metal layers of the D-mode and E-mode FET are in contact with the first etch stop layer. The D-mode and E-mode gate-sinking regions are beneath the respective first gate metal layers of the D-mode and E-mode gate electrode at least within the first etch stop layer. The first gate metal layer material of the D-mode is the same as that of the E-mode, where the first gate metal layer thickness of the E-mode is greater than that of the D-mode.

Abstract: A monolithic integration of enhancement mode (E-mode) and depletion mode (D-mode) field effect transistors (FETs) comprises a compound semiconductor substrate overlaid by an epitaxial structure overlaid by source and drain electrodes. The epitaxial structure includes from bottom to top sequentially a buffer layer, a channel layer, a Schottky barrier layer, a first etch stop layer, and a first cap layer. The respective first gate metal layers of the D-mode and E-mode FET are in contact with the first etch stop layer. The D-mode and E-mode gate-sinking regions are beneath the respective first gate metal layers of the D-mode and E-mode gate electrode at least within the first etch stop layer. The first gate metal layer material of the D-mode is the same as that of the E-mode, where the first gate metal layer thickness of the E-mode is greater than that of the D-mode.

Abstract: An integrated circuit with ESD protection comprises at least one ESD protection circuit block, which comprises a DC blocking capacitor connected in parallel with at least one compound semiconductor enhancement mode FET as an ESD protection device. The ESD protection circuit block that is built in an integrated circuit provides ESD protection while minimizing the generation of unwanted nonlinear signals resulting from the ESD protection. An integrated circuit comprises a high frequency circuit, a switching element, and two ESD protection circuit blocks, in which the high frequency circuit is connected between a first terminal and a second terminal for inputting or outputting the RF signals, the first ESD protection circuit block is connected from a branch node between the first terminal and the high frequency circuit to the switching element, and the second ESD protection circuit block is connected from the switching element to the ground.

Abstract: The present invention relates to compound semiconductor ESD protection devices of three types. The device comprises a multi-gate enhancement mode PET (E-PET). For the type I compound semiconductor ESD protection device, the source electrode is connected to the plural gate electrodes through at least one first resistor, and the drain electrode is connected to the plural gate electrodes through at least one second resistor. For the type II compound semiconductor ESD protection device, at least one of the plural gate electrodes are connected to at least one of the inter-gate regions between two adjacent gate electrodes through at least one fourth resistor. For the type compound semiconductor ESD protection device, the plural gate electrodes are connected to the source or drain electrodes through at least one seventh resistor. Any two gate electrodes in the three types of compound semiconductor ESD protection devices can be connected by a resistor.

Abstract: The present invention relates to compound semiconductor ESD protection devices using plural compound semiconductor E-FETs or compound semiconductor multi-gate E-FETs. The device comprises plural compound semiconductor E-FETs or multi-gate E-FETs, in which each of the gates is DC-connected to the source, drain, or an inter-gate region between two adjacent gates in the multi-gate E-FET through at least one first resistor, and at least one of the gates is AC-connected to the source, drain, or an inter-gate region between two adjacent gates in the multi-gate E-FET through a gate capacitor.

Abstract: An integrated circuit with ESD protection comprises at least one ESD protection circuit block, which comprises a DC blocking capacitor connected in parallel with at least one compound semiconductor enhancement mode FET as an ESD protection device. The ESD protection circuit block that is built in an integrated circuit provides ESD protection while minimizing the generation of unwanted nonlinear signals resulting from the ESD protection. An integrated circuit comprises a high frequency circuit, a switching element, and two ESD protection circuit blocks, in which the high frequency circuit is connected between a first terminal and a second terminal for inputting or outputting the RF signals, the first ESD protection circuit block is connected from a branch node between the first terminal and the high frequency circuit to the switching element, and the second ESD protection circuit block is connected from the switching element to the ground.

Abstract: The present invention relates to compound semiconductor ESD protection devices of three types. The device comprises a multi-gate enhancement mode FET (E-FET). For the type I compound semiconductor ESD protection device, the source electrode is connected to the plural gate electrodes through at least one first resistor, and the drain electrode is connected to the plural gate electrodes through at least one second resistor. For the type II compound semiconductor ESD protection device, the plural gate electrodes are connected to at least one of the inter-gate regions between two adjacent gate electrodes through at least one fourth resistor. For the type III compound semiconductor ESD protection device, the plural gate electrodes are connected to the source or drain electrodes through at least one seventh resistor. Any two gate electrodes in the three types of compound semiconductor ESD protection devices can be connected by a resistor.

Abstract: The present invention relates to compound semiconductor ESD protection devices using plural compound semiconductor E-FETs or compound semiconductor multi-gate E-FETs. The device comprises plural compound semiconductor E-FETs or multi-gate E-FETs, in which each of the gates is DC-connected to the source, drain, or an inter-gate region between two adjacent gates in the multi-gate E-FET through at least one first resister, and at least one of the gates is AC-connected to the source, drain, or an inter-gate region between two adjacent gates in the multi-gate E-FET through a gate capacitor.