Piezoelectric MEMS integration with GaN technology
AssigneeHRL Laboratories, LLC
InventorsSarabjit Mehta, David E. Grider, Wah S. Wong
Life of this patent
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Abstract
A process for fabricating a combined micro electromechanical/gallium nitride structure. The micro electromechanical structure comprises a piezoelectric device, such as a piezoelectric switch or a bulk acoustic wave device. According to the process, high Q compact bulk acoustic wave resonators can be built. The process is applicable to technologies such as tunable planar filter technology, amplifier technology and high speed analog-to-digital converters.
Claims32
A process for fabricating a combined micro electromechanical/gallium nitride (GaN) structure, the process comprising:
- providing a substrate;
- depositing a GaN layer on the substrate;
- obtaining a GaN transistor structure;
- depositing and patterning a first metal layer on the GaN layer;
- depositing a non-metal separation layer on the GaN layer and on the GaN transistor structure;
- patterning the non-metal separation layer to form a protective region to protect the GaN transistor structure;
- depositing a sacrificial layer on the protective region, the patterned first metal layer and at least a portion of the GaN layer so as to leave a further portion of the GaN layer between the protective region and the patterned first metal layer exposed;
- depositing and patterning a second metal layer on the sacrificial layer;
- depositing a support layer on the sacrificial layer, the patterned second metal layer and the exposed GaN layer;
- providing a piezoelectric structure on the support layer;
- patterning the support layer in proximity of the GaN transistor structure to provide access holes;
- removing the non-metal separation layer and the sacrificial layer from the proximity of the GaN transistor structure through the access holes;
- providing a metal overlay above the GaN transistor structure, the metal overlay forming a gate of the GaN transistor structure;
- providing a gate passivation layer above the gate of the GaN transistor structure;
- providing a further metal layer above the gate passivation layer;
- and
- removing the sacrificial layer between the first patterned metal layer and the second patterned metal layer.
An integrated gallium nitride (GaN) field emitter transistor (FET) disposed on a first surface of a gallium nitride (GaN) substrate and a piezoelectric micro electromechanical switch device also disposed on said first surface of said gallium nitride (GaN) substrate.
A process for fabricating a combined micro electromechanical/gallium nitride (GaN) structure, the process comprising:
- depositing a GaN layer;
- obtaining a GaN transistor structure on the GaN layer;
- forming a first metal contact pad on the GaN layer;
- forming a protective region around the GaN transistor structure;
- depositing a sacrificial layer on the protective region and the first metal contact pad;
- forming a second metal contact pad on the sacrificial layer;
- depositing a support layer on the sacrificial layer and the second metal contact pad;
- providing a piezoelectric structure on the support layer;
- removing the sacrificial layer from the proximity of the GaN transistor structure;
- patterning the piezoelectric structure in correspondence of the first metal contact pad and the second metal contact pad;
- forming a gate of the GaN transistor structure;
- providing a gate passivation layer above the gate of the GaN transistor structure;
- providing a further metal layer above the gate passivation layer;
- and
- removing the sacrificial layer between the first metal contact pad and the second metal contact pad.
A process for fabricating a combined gallium nitride (GaN)/piezoelectric structure comprising:
- obtaining a GaN structure on a GaN layer;
- forming a first metal contact pad on the GaN layer separated from the GaN structure;
- forming a protective region around the GaN structure;
- depositing a sacrificial layer on the protective region and the first metal contact pad;
- forming a second metal contact pad on the sacrificial layer;
- depositing a support layer on the sacrificial layer and the second metal contact pad;
- providing a piezoelectric switch structure on the support layer;
- removing the sacrificial layer from the proximity of the GaN structure;
- and
- patterning the piezoelectric switch structure in correspondence of the first metal contact pad and the second metal contact pad.
A process for fabricating a combined gallium nitride (GaN)/piezoelectric structure comprising:
- obtaining a GaN structure on a GaN layer;
- forming a first metal contact pad on the GaN layer separated from the GaN structure;
- forming a protective region around the GaN structure;
- depositing a sacrificial layer on the protective region and the first metal contact pad;
- forming a second metal contact pad on the sacrificial layer;
- depositing a support layer on the sacrificial layer and the second metal contact pad;
- providing a piezoelectric bulk acoustic wave resonator structure on the support layer;
- removing the sacrificial layer from the proximity of the GaN structure;
- and
- patterning the piezoelectric switch structure in correspondence of the first metal contact pad and the second metal contact pad.
A process for fabricating a combined micro electromechanical/gallium nitride (GaN) structure, the process comprising:
- providing a substrate;
- depositing a GaN layer on the substrate;
- obtaining a GaN transistor structure;
- depositing a non-metal separation layer on the GaN layer in correspondence of the GaN transistor structure;
- patterning the non-metal separation layer to form a protective region around the GaN transistor structure;
- depositing a sacrificial layer on at least a portion of the GaN layer and on the protective region;
- creating at least a cavity in the sacrificial layer;
- depositing a support layer on the sacrificial layer and the cavity;
- providing a piezoelectric structure on the support layer;
- patterning the support layer in proximity of the GaN transistor structure to provide access holes;
- removing the non-metal separation layer and the sacrificial layer from the proximity of the GaN transistor structure through the access holes;
- patterning the piezoelectric structure in correspondence of a patterned first metal layer and patterned second metal layer;
- providing a metal overlay above the GaN transistor structure, the metal overlay forming a gate of the GaN transistor structure;
- providing a gate passivation layer above the gate of the GaN transistor structure;
- providing a further metal layer above the gate passivation layer;
- and
- removing the sacrificial layer between the GaN layer and the support layer.
An integrated gallium nitride (GaN) field emitter transistor (FET) disposed on a first surface of a gallium nitride (GaN) substrate and a bulk acoustic wave (BAW) device also disposed on said first surface of said gallium nitride (GaN) substrate.
A process for fabricating a combined micro electromechanical/gallium nitride (GaN) structure, the process comprising:
- depositing a GaN layer;
- obtaining a GaN transistor structure on the GaN layer;
- forming a first contact pad on the GaN layer;
- forming a protective region around the GaN transistor structure;
- depositing a sacrificial layer on the protective region and the first contact pad;
- forming a second contact pad on the sacrificial layer;
- depositing a support layer on the sacrificial layer and the second contact pad;
- providing a piezoelectric structure on the support layer;
- removing the sacrificial layer from the proximity of the GaN transistor structure;
- patterning the piezoelectric structure in correspondence of the first contact pad and the second contact pad;
- and
- removing the sacrificial layer between the first contact pad and the second contact pad.
Dependencies are inferred from the claim text.