Motorola Corporation

Frank K Baker

James D Hayden

James R Pfiester

Robert Bruce Davies

Richard D Sivan

Kent J Cooper

Craig S Lage

Thomas C Mele

James David Burnett

Howard C Kirsch

Louis C Parrillo

Peter J Zdebel

Michael P Woo

Stephen S Poon

Andreas A Wild

Jon J Candelaria

Vida Ilderem

Wayne M Paulson

Yasunobu Kosa

Jeffrey L Klein

Diann M Dow

Juan Buxo

Mark D Griswold

Thomas F McNelly

Chandrasekhara Sudhama

Patrick J Holly

Charles F Hart

Iksung Lim

James E Prendergast

A graded-channel semiconductor device (10) includes a substrate region (11) having a major surface (12). A source region (13) and a drain region (14) are formed in the substrate region (11) and are spaced apart to form a channel region (16). A doped region (18) is formed in the channel region (16) and is spaced apart from the source region (13), the drain region (14), and the major surface (12). The doped region (18) has the same conductivity type as the channel region (16), but has a higher dopant concentration. The device (10) exhibits an enhanced punch-through resistance and improved performance compared to prior art short channel structures.

Graded-channel semiconductor device

An insulated gate field effect transistor (10) having a reduced gate to drain capacitance and a method of manufacturing the field effect transistor (10). A dopant well (13) is formed in a semiconductor substrate (11) and a drain extension region (25) is formed in the dopant well (13). An oxide layer (26) is formed on the dopant well (13) wherein the oxide layer (26) has a thickness of at least 400 angstroms. A gate structure (61) having a gate shunt portion (32) over a thinned portion of the oxide (26) and a gate extension portion (58) over an unthinned portion of the oxide (26). The thinned portion of the oxide (26) forms a gate oxide of the field effect transistor (10) and the unthinned portion lowers a capacitance of the gate shunt portion (32) of the field effect transistor (10).

Method of making an insulated gate semiconductor device

An insulated gate field effect transistor (10) having an reduced gate to drain capacitance and a method of manufacturing the field effect transistor (10). A dopant well (13) is formed in a semiconductor material (11). A gate oxide layer (26) is formed on the dopant well (13) wherein the gate oxide layer (26) and a gate structure (41) having a gate contact portion (43) and a gate extension portion (44). The gate contact portion (43) permits electrical contact to the gate structure (41), whereas the gate extension portion (44) serves as the active gate portion. A portion of the gate oxide (26) adjacent the gate contact portion (43) is thickened to lower a gate to drain capacitance of the field effect transistor (10) and thereby increase a bandwidth of the insulated gate field effect transistor (10).

Insulated gate semiconductor device and method of manufacture

A static-random-access memory cell comprising floating node capacitors is disclosed. In one embodiment, the storage nodes acts as the first plates for the floating node capacitors, and a conductive member acts as the second plates for the floating node capacitors. The conductive member also electrically connects the second plates together, but is not electrically connected to other parts of the memory cell. In another embodiment, a conductive member acts as the second plates of a plurality of memory cells. The conductive member also electrically connects the second plates together, but is not electrically connected to other parts of the memory cells. Processes for forming the memory cells is also disclosed.

Process for forming a static-random-access memory cell

The present invention includes an integrated circuit having a self-aligned contact that makes contact to both a region within the substrate and a capacitor plate of a capacitor that is adjacent to the doped region. The present invention also includes a static-random-access memory cell with a capacitor having a first plate and a second plate. The first plate includes a first plate section of a gate electrode of a transistor, and the second plate includes a first conductive member that is substantially coincident with the first plate section. The second plate may be formed over a gate electrode of a latch transistor or over a word line. The disclosure includes methods of forming the integrated circuit and the static-random-access memory cell.

Static-random-access memory cell and an integrated circuit having a

Process forming an integrated circuit

A pair of first and second thin film transistors (TFTs). The transistors are formed from a first continuous, conductive region (38) and a second continuous, conductive region (39) which underlies the first conductive region (38). The first transistor has a source region (50), a drain region (54), and a channel region (52) created from three distinct and separate regions of conductor region (39). The first transistor has a gate region (53) that overlies the channel region (52). The gate region (53) is formed from a distinct region of conductive region (38). The second transistor has a source region (44), a drain region (48), and a channel region (46) which are created from three distinct and separate regions of conductor region (38). The second transistor has a gate region (47) that underlies the channel region (46). The gate region (47) is formed from a distinct region of conductive region (39).

Method for compactly laying out a pair of transistors

Compact transistor pair layout and method thereof

A semiconductor device (10) has a bipolar transistor merged with an MOS transistor, the two transistors being separated essentially by a sidewall spacer and the bipolar transistor being self-aligned to the MOS transistor. The MOS transistor includes a gate (22) and a sorce region (38). A drain region of the MOS transistor is also an active base region (27) of the bipolar transistor. The bipoloar transistor further includes a first emitter region (40) formed in the active base region and a second emitter region (32) which is formed on the first emitter region and partially overlies the MOS transistor gate. The second emitter region is separated from the gate by a sidewall spacer (29) and an overlying dielectric layer (23).

Semiconductor device having merged bipolar and MOS transistors and

In forming a lightly-doped drain (LDD) transistor there is first formed a thin polysilicon layer over a gate oxide on an active region. A masking layer is deposited and selectively etched to expose a middle portion of the polysilicon layer. This structure can be used as part of a process which results ina formation of an inverse-T transistor or a conventional LDD structure which is formed by disposable sidewall spacers. The exposed middle portion of the polysilicon layer is used to form a polysilicon gate by selective polysilicon deposition. The exposed middle portion can be implanted through for the channel implant, thus providing self-alignment to the source/drain implants. Sidewall spacers can be formed inside the exposed portion to reduce the channel length. These sidewall spacers can be nitride to provide etching selectivity between the sidewall spacer and the conveniently used low temperature oxide (LTO) mask.

Method of fabricating MOS transistors using selective polysilicon

The disclosed invention is a method for fabricating a multi-layer semiconductor device using selective planarization. In accordance with one embodiment of the invention, conductive members are formed on a substrate and a first insulating layer is deposited onto the substrate and the conductive members. A second insulating layer, which has a lower flow temperature than the flow temperature of the first layer, is deposited onto the first layer. A photoresist mask is patterned and developed to form a window which exposes an area between the conductive members. The device is preferentially etched such that only the exposed areas of the second insulating layer are removed, leaving the first insulating layer intact. An anisotropic etch is used to remove portions of the first insulating layer, leaving spacers along the edges of the conductive members. The photoresist mask is removed and a heating step is performed which flows the remaining portions of the second insulating layer, but not the first layer. Since the second insulating material remains in only selective areas, the process is termed selective planarization. The method provides the benefit that areas which are to be etched to form contact hole or vias are not planarized, unlike existing blanket planarization methods, and a self-aligned contact is formed between the conductive members to the substrate.

Method for forming a multi-layer semiconductor device using selective

The invention provides a method for patterning a submicron opening in a layer of semiconductor material. The method comprises use of conventional photolithography to position a sidewall spacer in a predetermined location on a semiconductor device. A layer of cobalt is selectively reacted with an underlying layer to form an image reversal layer which functions as a hard mask. The submicron features are then transferred into the underlying layer of semiconducting material by etching.

Method for patterning submicron openings using an image reversal layer

In forming a lightly-doped drain (LDD) transistor there is first formed a thin polysilicon layer over a gate oxide on an active region. A masking layer is deposited and selectively etched to expose a middle portion of the polysilicon layer. This structure can be used as part of a process which results in a formation of an inverse-T transistor or a conventional LDD structure which is formed by disposable sidewall spacers. The exposed middle portion of the polysilicon layer is used to form a polysilicon gate by selective polysilicon deposition. The exposed middle portion can be implanted through for the channel implant, thus providing self-alignment to the source/drain implants. Sidewall spacers can be formed inside the exposed portion to reduce the channel length. These sidewall spacers can be nitride to provide etching selectivity between the sidewall spacer and the conveniently used low temperature oxide (LTO) mask.

MOS transistors using selective polysilicon deposition

An LDD transistor is formed by using a process which insures that a layer of gate oxide is not inadvertently etched into and is not ruptured by static electrical charges. At least two thicknesses of gate electrode material of varying doping levels are formed over a layer of gate oxide which is above a semiconductor substrate. A chemical etch is utilized wherein by monitoring a ratio of chemical product and chemical reactant of the chemical etch reactions, specific endpoints in the etching of the gate electrode material can be easily detected. A small layer of gate electrode material is allowed to remain over the gate oxide layer during ion implanting and the formation and removal of gate sidewall spacers used in fabricating an LDD transistor. After formation of most of the LDD transistor, the remaining protective thickness of gate electrode material is removed and the exposed gate oxide layer is exposed to a final oxidizing anneal step. In other forms, an inverse-T gate structure LDD transistor is formed, and an LDD transistor is formed via a process having a reduced number of ion implants steps.

LDD transistor process having doping sensitive endpoint etching

An erasable programmable read only memory (EPROM) cell having a floating gate and a control gate where the floating gate and the control gate are deliberately offset or asymmetrical from the source/drain and drain/source regions in the substrate. During programming, the source region is the one spaced apart from the gates while the drain region is aligned thereto. This orientation produces high gate currents to provide faster programming. During a read operation the aligned region now becomes the source and the spaced apart region becomes the drain to provide high drain currents for fast access. The asymmetrical EPROM cells of the present invention may be readily made using conventional spacer technology.

Growing community of inventors

Austin, TX, United States of America

Frank K Baker