Texas Instruments Corporation

Triquint Semiconductor Texas, Inc.

Shou-Kong Fan

Darrell G Hill

William U Liu

Ali Khatibzadeh

Timothy S Henderson

Damian Costa

Hin-Fai Chau

Walter Marvin Duncan

Tsen H Lin

Chih-Chen Cho

Chin-Chen Cho

A bipolar transistor includes a passivating layer of material 40 in the base structure 42 that serves to cover the extrinsic base region of the transistor. The passivating layer 40 is formed of a material having a wider bandgap than the base layer 44, and is heavily doped with the same doping type (n or p) as the base layer. The invention is advantageous in that the base contacts 48 of the device are made directly to the passivating layer 40 and are not in direct contact with the base layer 44. This eliminates the need for alloyed contacts and the concomitant reliability problems associated with spiking contacts. In addition, the invention is completely compatible with self-aligned production techniques.

Method of fabricating a bipolar transistor

This is a method of fabricating a bipolar transistor on a wafer. The method can comprise: forming a doped emitter contact layer 31 on a substrate 30; forming a doped emitter layer 32 on top of the emitter contact layer, the emitter layer doped same conductivity type as the emitter contact layer; forming a doped base epilayer 34 on top of the emitter layer, the base epilayer doped conductivity type opposite of the emitter layer; forming a doped collector epilayer 36, the collector epilayer doped conductivity type opposite of the base layer to form the bipolar transistor; forming an collector contact 38 on top of the collector layer; forming a base contact 40 on top of the base layer; forming a emitter contact 44 on top of the emitter contact layer; and selective etching the emitter layer to produce an undercut 45 beneath the base layer.

Reducing junction capacitance and increasing current gain in

Method for reducing junction capacitance and increasing current gain in

A method and apparatus for producing photoluminescence emissions (68) from thin CaF.sub.2 films grown on either silicon or silicon/aluminum substrate shows narrow emission linewidth and high emission intensities for CaF.sub.2 with thickness as low as 0,2 .mu.m, The preferred embodiment is doped with a rare-earth such as Nd.

Apparatus and method for generating photluminescence emission lines from

Bipolar transistor

Generally, and in one form of the invention, a method is disclosed for reducing base-to-emitter leakage in a bipolar transistor having an active region 22 bounded by an isolation implant boundary 24, said method comprising arranging an emitter contact 26 and a base contact 36 such that at a crossing of the contacts over the implant boundary, a leakage current between the contacts along the boundary is limited by a necessity to transit the thickness of a layer of material, and whereby said transistor exhibits improved gain, noise performance, and reliability.

Method to reduce emitter-base leakage current in bipolar transistors

Method for making collector up bipolar transistors having reducing

In one form of the invention, a method is disclosed for removing portions of successive layers of GaAs 34 and GaInP 32 comprising the steps of: performing an anisotropic reactive ion etch on the GaAs layer; and performing an isotropic wet etch on the GaInP layer, whereby a mesa formed as a result of the reactive ion etch and the wet etch has substantially vertical sidewalls, and further whereby GaInP/GaAs structures having dimensions of less than approximately 3.0 .mu.m may be fabricated.

Method for fabricating GaInP/GaAs structures

A method and apparatus for producing photoluminescence emissions (68) from thin CaF.sub.2 films grown on either silicon or silicon/aluminum substrate shows narrow emission linewidth and high emission intensities for CaF.sub.2 with thickness as low as 0.2 .mu.m. The preferred embodiment is doped with a rare-earth such as Nd.

Method for generating photoluminescence emission lines from transition

A method of making a transistor comprising the steps of providing a structure having a collector layer 3, a base layer 5, and an emitter layer 7, one atop the other, forming a contact 9 on the emitter layer, removing a portion of the emitter layer to leave a relatively thick mesa region 13 with the contact thereon, a surrounding relatively thin ledge region 11 and an exposed portion of the base layer 5 and forming a contact on the exposed portion of the base layer 5. The emitter layer 7 is preferably GaInP, and preferably Ga.sub.x In.sub.1-x P, wherein x is in the range of approximately 0.50 to 0.52, and the base 5 is preferably GaAs. The ledge portion 11 has a thickness of about 700 Angstroms.

Growing community of inventors

Richardson, TX, United States of America

Shou-Kong Fan