International Business Machines Corporation

Feng-Yi Huang

Devendra K Sadana

Jack Oon Chu

Steven John Koester

Gregory Gower Freeman

David C Ahlgren

Adam D Ticknor

A method of fabricating high-quality, substantially relaxed SiGe-on-insulator substrate is provided by implanting oxygen into a Si/SiGe multilayer heterostructure which comprises alternating Si and SiGe layers. Specifically, the high quality, relaxed SiGe-on-insulator is formed by implanting oxygen ions into a multilayer heterostructure which includes alternating layers of Si and SiGe. Following, the implanting step, the multilayer heterostructure containing implanted oxygen ions is annealed, i.e., heated, so as to form a buried oxide region predominately within one of the Si layers of the multilayer structure.

Method of forming a SiGe-on-insulator substrate using separation by implantation of oxygen

A silicon-germanium base capable of use in heterojunction bipolar transistor includes a silicon substrate having a mesa surrounded by a trench. The mesa has a top surface and a silicon-germanium layer is disposed only on the top surface of the mesa. In addition, a heterojunction bipolar transistor includes the silicon-germanium base as described.

Heterojunction bipolar transistor with silicon-germanium base

A process for forming a bipolar transistor with a raised extrinsic base, an emitter, and a collector integrated with a CMOS circuit with a gate. An intermediate semiconductor structure is provided having CMOS and bipolar areas. An intrinsic base layer is provided in the bipolar area. A base oxide is formed across, and a sacrificial emitter stack silicon layer is deposited on, both the CMOS and bipolar areas. A photoresist is applied to protect the bipolar area and the structure is etched to remove the sacrificial layer from the CMOS area only such that the top surface of the sacrificial layer on the bipolar area is substantially flush with the top surface of the CMOS area. Finally, a polish stop layer is deposited having a substantially flat top surface across both the CMOS and bipolar areas suitable for subsequent chemical-mechanical polishing (CMP) to form the raised extrinsic base.

Bipolar transistor with raised extrinsic base fabricated in an integrated BiCMOS circuit

A process for forming a silicon-germanium base of a heterojunction bipolar transistor. First, a silicon substrate having a mesa surrounded by a trench is formed. Next, a silicon-germanium layer is deposited on the substrate and the portion of the silicon-germanium layer adjacent the mesa is removed to form the silicon-germanium base. In a second embodiment, the process comprises the steps of forming a silicon substrate having a mesa surrounded by a trench, forming a dielectric layer in the trench adjacent the mesa, and growing a silicon-germanium layer on the mesa top surface using selective epitaxial growth to form the silicon-germanium base.

Process for forming a silicon-germanium base of a heterojunction bipolar transistor

A BiCMOS integrated circuit is formed with CMOS transistors on an SOI substrate in a silicon layer having a standard thickness of 0.1 &mgr;m to 0.2 &mgr;m and with Bipolar SiGe transistors formed in an epitaxial layer nominally 0.5 &mgr;m thick. The CMOS transistors are formed first with standard processing, then covered with an insulating film. The insulating film is stripped in the bipolar areas and an epitaxial SiGe layer is deposited on the Si substrate. The bipolar transistors are formed using the SiGe epi layer for the base and having an encapsulated structure for device isolation using shallow isolation trenches and the buried oxide.

Silicon-germanium BiCMOS on SOI

A process for forming a silicon-germanium base of a heterojunction bipolar transistor. First, a silicon substrate having a mesa surrounded by a trench is formed. Next, a silicon-germanium layer is deposited on the substrate and the portion of the silicon-geranium layer adjacent the mesa is removed to form the silicon-germanium base. In a second embodiment, the process comprises the steps of forming a silicon substrate having a mesa surrounded by a trench, forming a dielectric layer in the trench adjacent the mesa, and growing a silicon-germanium layer on the mesa top surface using selective epitaxial growth to form the silicon-germanium base.

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Hacienda Heights, CA, United States of America

Feng-Yi Huang