Hewlett-packard Company

Other

Winbond Electronics Corporation

Chen-Hsi Lin

Chi-Kwan Lau

Gregory N Burton

Donald L Packwood

Ashor Kapoor

A process for simultaneously forming a self-aligned contact, a local interconnect and a self-aligned silicide in a semiconductor device. An oxide layer is deposited over a gate structure, a source region and a drain region formed on a substrate of the semiconductor device. The gate structure may be a multi-layer structure including a polysilicon gate, a silicon nitride layer and a tungsten silicide layer. The oxide layer deposited over the gate, source and drain is etched to define portions of the oxide layer which will form contact areas of a self-aligned contact and a local interconnect of the semiconductor device. An amorphous silicon layer is then deposited over the etched oxide layer to a thickness selected such that substantially the entire thickness of remaining portions of the amorphous silicon layer will be consumed during a subsequent silicidation reaction. The amorphous silicon layer is etched to remove portions of the amorphous silicon layer which will not be used to form a portion of the self-aligned contact and local interconnect, as well as remaining non-contact area portions of the underlying oxide layer. A metal layer is deposited over the etched amorphous silicon layer, and an annealing process is applied such that the etched amorphous silicon layer and the deposited metal layer react to provide a silicide layer which forms a portion of the self-aligned contact and the local interconnect. The annealing process also causes the deposited metal layer to react with exposed source and/or drain regions to thereby form a self-aligned silicide.

Process for simultaneous formation of silicide-based self-aligned

The present invention provides a buried layer fabrication sequence suitable for bipolar and BiCMOS applications. The buried layer fabrication sequence for forming a buried layer having a first conductivity type includes the steps of: forming a first dielectric layer on a semiconductor substrate, the semiconductor substrate having a second conductivity type; forming a first mask layer having openings on top of the first dielectric layer, wherein the openings in the first mask layer are positioned over the regions where the first buried layer is formed; exposing the semiconductor substrate in the regions where openings in the first mask layer are formed; forming a second dielectric layer; removing the second dielectric layer; and forming a semiconductor layer.

Method for formation of a buried layer for a semiconductor device

A method of fabricating a BiCMOS device in which PMOS and NMOS transistors are formed prior to a base/emitter structure of a bipolar transistor. In forming the base/emitter structure, a blanket implant of a first impurity is introduced into a base region of a semiconductor substrate. An insulating layer is deposited and then patterned to expose a portion of the base region at an emitter window. A polysilicon layer is deposited on the insulating layer and into the emitter window. The polysilicon layer is patterned to provide the desired configuration at the emitter window, whereafter the remaining polysilicon acts as a mask for etching of the insulating layer. Thus, etching of the insulating layer is performed in a self-aligning manner. Self-alignment is also utilized in providing a base-link region and in providing a silicide layer.

Method of separately fabricating a base/emitter structure of a BiCMOS

A method of plasma etching tungsten containing films such as is found in semiconductor interconnects. The etch method is conducted under reactive ion etch conditions in a plasma etch reactor using a gas mixture of CF.sub.4 and O.sub.2. The O.sub.2 preferably makes up 20% to 60% of the gas mixture by volume. The etch method is highly selective to titanium disilicide, titanium nitride and silicon dioxide.

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Cupertino, CA, United States of America

Chen-Hsi Lin