Bipolar transistor with isolation and direct contacts
AssigneeInternational Business Machines Corporation
InventorsDavid C. Ahlgren, Gregory G. Freeman, Francois Pagette, Christopher M. Schnabel, Anna W. Topol
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Abstract
A bipolar transistor has a collector that is contacted directly beneath a base-collector junction by metallization to reduce collector resistance. A conventional reach-through and buried layer, as well as their associated resistance, are eliminated. The transistor is well isolated, nearly eliminating well-to-substrate capacitance and device-to-device leakage current. The structure provides for improved electrical performance, including improved fT, Fmax and drive current.
Claims8
A method of fabricating a device, comprising:
- depositing a base layer on a first side of a collector layer;
- depositing an emitter layer on the base layer;
- depositing a silicide layer on a second side of the collector;
- depositing a first oxide layer on the silicide layer on the second side of the collector layer;
- etching a via through the first oxide layer from a top surface of the first oxide layer to the silicide layer on the second side of the collector layer;
- filling the via with a conductor to form an electrical pathway to the collector through the first oxide layer;
- bonding the second side of the collector layer to a first substrate prior to the deposition of the first oxide layer;
- prior to the bonding step depositing an oxide layer around at least one side of the collector layer;
- depositing a passivation layer on the oxide layer and base layer and emitter layer;
- and
- depositing at least one metal contact on the passivation layer and bonding the at least one metal contact to a substrate and removing at least a portion of the first substrate.
A method of fabricating a device, comprising:
- depositing a base layer on a first side of a collector layer;
- depositing an emitter layer on the base layer;
- depositing a first oxide layer on the second side of the collector layer;
- etching a via through the first oxide layer from a top surface of the first oxide layer to the second side of the collector layer;
- filling the via with a conductor to form an electrical pathway to the collector through the first oxide layer;
- bonding the second side of the collector layer to a first substrate prior to the deposition of the first oxide layer;
- prior to the bonding step depositing a oxide layer around at least one side of the collector layer;
- depositing a passivation layer on the oxide layer and base layer and emitter layer;
- and
- depositing at least one metal contact on the passivation layer and bonding the at least one metal contact to a substrate and removing at least a portion of the first substrate.
Dependencies are inferred from the claim text.