Abstract: A method for precise thinning to form a recess to a precise depth in a crystalline silicon layer, which can be used to form various devices, such as MOSFET devices, includes the following steps. Form a patterning mask with a window therethrough over the top surface of the silicon layer. Form an amorphized region in the top surface of the silicon layer below the window. Selectively etch away the amorphized region of the silicon layer to form a recess in the surface of the silicon layer, and remove the patterning mask. In the case of an MOSFET device form a hard mask below the patterning mask with the window extending therethrough. Then create sidewall spacers in the window through the hard mask and form a gate electrode stack in the window. Then remove the hard mask and form the source/drain extensions, halos and regions plus silicide and complete the MOSFET device.

Abstract: A method for forming a CMOS well structure including forming a plurality of first conductivity type wells over a substrate, each of the plurality of first conductivity type wells formed in a respective opening in a first mask. A cap is formed over each of the first conductivity type wells, and the first mask is removed. Sidewall spacers are formed on sidewalls of each of the first conductivity type wells. A plurality of second conductivity type wells are formed, each of the plurality of second conductivity type wells are formed between respective first conductivity type wells. A plurality of shallow trench isolations are formed between the first conductivity type wells and second conductive type wells. The plurality of first conductivity type wells are formed by a first selective epitaxial growth process, and the plurality of second conductivity type wells are formed by a second selective epitaxial growth process.

Abstract: A method for modulating the stress caused by bird beak formation of small width devices by a nitrogen plasma treatment. The nitrogen plasma process forms a nitride liner about the trench walls that serves to prevent the formation of bird beaks in the isolation region during a subsequent oxidation step. In one embodiment, the plasma nitridation process occurs after trench etching, but prior to trench fill. In yet another embodiment, the plasma nitridation process occurs after trench fill. In yet another embodiment, a block mask is formed over predetermined active areas of the etched substrate prior to the plasma nitridation process. This embodiment is used in protecting the PFET device area from the plasma nitridation process thereby providing a means to form a PFET device area in which stress caused by bird beak formation increases the device performance of the PFET.

Abstract: An RSD FET device with a recessed channel is formed with a raised silicon S/D and a gate electrode structure on an SOI structure by the steps as follows. Form a SiGe layer over the silicon layer and a RSD layer over the SiGe. Etch through the RSD layer and the SiGe to form a gate electrode space reaching down the silicon layer. Form a pair of RSD regions separated by the gate electrode space. Line the walls of the gate electrode space with an internal etch stop layer and an inner sidewall spacers. Form a gate electrode inside the inner sidewall spacers on the silicon layer. Form external sidewall spacers adjacent to the gate electrode between the RSD regions next to the inner sidewall spacers, and dope the RSD regions, whereby a recessed channel is formed in the SOI silicon layer between the raised source/drain regions above the SiGe layer.

Abstract: A method is provided for forming an SOI MOSFET device with a silicon layer formed on a dielectric layer with a gate electrode stack, with sidewall spacers on sidewalls of the gate electrode stack and raised source/drain regions formed on the surface of the silicon layer. The gate electrode stack comprises a gate electrode formed of polysilicon over a gate dielectric layer formed on the surface of the silicon layer. A plug of dielectric material is formed in a notch in a cap layer above the gate polysilicon. The sidewalls of the gate electrode is covered by the sidewall spacers which cover a portion of the plug for the purpose of eliminating the exposure of the gate polysilicon so that formation of spurious epitaxial growth during the formation of raised source/drain regions is avoided.

Abstract: A method for precise thinning to form a recess to a precise depth in a crystalline silicon layer, which can be used to form various devices, such as MOSFET devices, includes the following steps. Form a patterning mask with a window therethrough over the top surface of the silicon layer. Form an amorphized region in the top surface of the silicon layer below the window. Selectively etch away the amorphized region of the silicon layer to form a recess in the surface of the silicon layer, and remove the patterning mask In the case of an MOSFET device form a hard mask below the patterning mask with the window extending therethrough. Then create sidewall spacers in the window through the hard mask and form a gate electrode stack in the window. Then remove the hard mask and form the source/drain extensions, halos and regions plus silicide and complete the MOSFET device.

Abstract: A method for modulating the stress caused by bird beak formation of small width devices by a nitrogen plasma treatment. The nitrogen plasma process forms a nitride liner about the trench walls that serves to prevent the formation of bird beaks in the isolation region during a subsequent oxidation step. In one embodiment, the plasma nitridation process occurs after trench etching, but prior to trench fill. In yet another embodiment, the plasma nitridation process occurs after trench fill. In yet another embodiment, a block mask is formed over predetermined active areas of the etched substrate prior to the plasma nitridation process. This embodiment is used in protecting the PFET device area from the plasma nitridation process thereby providing a means to form a PFET device area in which stress caused by bird beak formation increases the device performance of the PFET.

Abstract: A method for modulating the stress caused by bird beak formation of small width devices by a nitrogen plasma treatment. The nitrogen plasma process forms a nitride liner about the trench walls that serves to prevent the formation of bird beaks in the isolation region during a subsequent oxidation step. In one embodiment, the plasma nitridation process occurs after trench etching, but prior to trench fill. In yet another embodiment, the plasma nitridation process occurs after trench fill. In yet another embodiment, a block mask is formed over predetermined active areas of the etched substrate prior to the plasma nitridation process. This embodiment is used in protecting the PFET device area from the plasma nitridation process thereby providing a means to form a PFET device area in which stress caused by bird beak formation increases the device performance of the PFET.

Abstract: Silicon on insulator (SOI) field effect transistors (FET) with a shared body contact, a SRAM cell and array including the SOI FETs and the method of forming the SOI FETs. The SRAM cell has a hybrid SOI/bulk structure wherein the source/drain diffusions do not penetrate to the underlying insulator layer, resulting in a FET in the surface of an SOI layer with a body or substrate contact formed at a shared contact. FETs are formed on SOI silicon islands located on a BOX layer and isolated by shallow trench isolation (STI). NFET islands in the SRAM cells include a body contact to a P-type diffusion in the NFET island. Each NFET in the SRAM cells include at least one shallow source/drain diffusion that is shallower than the island thickness. A path remains under the shallow diffusions between NFET channels and the body contact. The P-type body contact diffusion is a deep diffusion, the full thickness of the island. Bit line diffusions shared by SRAM cells on adjacent wordlines may be deep diffusions.

Abstract: Disadvantages of the floating body of a SOI MOSFET are addressed by providing a pocket halo implant of indium beneath the gate and in the channel region of the semiconductor SOI layer of the MOSFET. Also provided is the method for fabricating the device.

Abstract: A semiconductor chip includes a semiconductor substrate having a rectifying contact diffusion and a non-rectifying contact diffusion. A halo diffusion is adjacent the rectifying contact diffusion and no halo diffusion is adjacent the non-rectifying contact diffusion. The rectifying contact diffusion can be a source/drain diffusion of an FET to improve resistance to punch-through. The non-rectifying contact diffusion may be an FET body contact, a lateral diode contact, or a resistor or capacitor contact. Avoiding a halo for non-rectifying contacts reduces series resistance and improves device characteristics. In another embodiment on a chip having devices with halos adjacent diffusions, no halo diffusion is adjacent a rectifying contact diffusion of a lateral diode, significantly improving ideality of the diode and increasing breakdown voltage.

Abstract: A T-RAM array having a planar cell structure is presented. The T-RAM array includes n-MOS and p-MOS support devices which are fabricated by sharing process implant steps with T-RAM cells of the T-RAM array. A method is also presented for fabricating the T-RAM array having the planar cell structure. The method entails simultaneously fabricating a first portion of a T-RAM cell and the n-MOS support device; simultaneously fabricating a second portion of the T-RAM cell and the p-MOS support device; and finishing the fabrication of the T-RAM cell by interconnecting the T-RAM cell with the p-MOS and n-MOS support devices. The first portion of the T-RAM cell is a transfer gate and the second portion of the T-RAM cell is a gated-lateral thyristor storage element. Accordingly, process steps in fabricating the T-RAM cells are shared with process steps in fabricating the n-MOS and p-MOS support devices. The n-MOS and p-MOS support devices refer to sense amplifiers, wordline drivers, column and row decoders, etc.

Abstract: Disadvantages of the floating body of a SOI MOSFET are addressed by providing a pocket halo implant of indium beneath the gate and in the channel region of the semiconductor SOI layer of the MOSFET. Also provided is the method for fabricating the device.

Abstract: Silicon on insulator (SOI) field effect transistors (FET) with a shared body contact, a SRAM cell and array including the SOI FETs and the method of forming the SOI FETs. The SRAM cell has a hybrid SOI/bulk structure wherein the source/drain diffusions do not penetrate to the underlying insulator layer, resulting in a FET in the surface of an SOI layer with a body or substrate contact formed at a shared contact. FETs are formed on SOI silicon islands located on a BOX layer and isolated by shallow trench isolation (STI). NFET islands in the SRAM cells include a body contact to a P-type diffusion in the NFET island. Each NFET in the SRAM cells include at least one shallow source/drain diffusion that is shallower than the island thickness. A path remains under the shallow diffusions between NFET channels and the body contact. The P-type body contact diffusion is a deep diffusion, the full thickness of the island. Bit line diffusions shared by SRAM cells on adjacent wordlines may be deep diffusions.

Abstract: Silicon on insulator (SOI) field effect transistors (FET) with a shared body contact, a SRAM cell and array including the SOI FETs and the method of forming the SOI FETs. The SRAM cell has a hybrid SOI/bulk structure wherein the source/drain diffusions do not penetrate to the underlying insulator layer, resulting in a FET in the surface of an SOI layer with a body or substrate contact formed at a shared contact. FETs are formed on SOI silicon islands located on a BOX layer and isolated by shallow trench isolation (STI). NFET islands in the SRAM cells include a body contact to a P-type diffusion in the NFET island. Each NFET in the SRAM cells include at least one shallow source/drain diffusion that is shallower than the island thickness. A path remains under the shallow diffusions between NFET channels and the body contact. The P-type body contact diffusion is a deep diffusion, the full thickness of the island. Bit line diffusions shared by SRAM cells on adjacent wordlines may be deep diffusions.

Abstract: A method for forming a substrate contact in a substrate that includes a silicon on insulator region. A shallow isolation trench is formed in the silicon on insulator substrate. The shallow isolation trench is filled. Photoresist is deposited on the substrate. A contact trench is formed in the substrate through the filled shallow isolation trench, silicon on insulator, and silicon substrate underlying the silicon on insulator region. The contact trench is filled, wherein the material filling the contact trench forms a contact to the silicon substrate.

Abstract: A semiconductor chip includes a semiconductor substrate having a rectifying contact diffusion and a non-rectifying contact diffusion. A halo diffusion is adjacent the rectifying contact diffusion and no halo diffusion is adjacent the non-rectifying contact diffusion. The rectifying contact diffusion can be a source/drain diffusion of an FET to improve resistance to punch-through. The non-rectifying contact diffusion may be an FET body contact, a lateral diode contact, or a resistor or capacitor contact. Avoiding a halo for non-rectifying contacts reduces series resistance and improves device characteristics. In another embodiment on a chip having devices with halos adjacent diffusions, no halo diffusion is adjacent a rectifying contact diffusion of a lateral diode, significantly improving ideality of the diode and increasing breakdown voltage.

Abstract: A method of manufacturing a metal oxide semiconductor field effect transistor (MOSFET). The method forms an insulator layer over a substrate and a doped layer over the insulator layer. Further, the invention patterns a conductor layer over the doped layer. The conductor layer includes gate conductors. The invention implants a second impurity through the conductor layer and into the doped layer. The second impurity is of an opposite type than that of the first type of impurity. Also, the second impurity decreases the effective concentration of the first impurity in the doped layer. The amount of the second type of impurity that penetrates through the conductor layer into the doped layer changes depending upon the length of the gate conductors within the conductor layer.

Abstract: A semiconductor chip includes a semiconductor substrate having a rectifying contact diffusion and a non-rectifying contact diffusion. A halo diffusion is adjacent the rectifying contact diffusion and no halo diffusion is adjacent the non-rectifying contact diffusion. The rectifying contact diffusion can be a source/drain diffusion of an FET to improve resistance to punch-through. The non-rectifying contact diffusion may be an FET body contact, a lateral diode contact, or a resistor or capacitor contact. Avoiding a halo for non-rectifying contacts reduces series resistance and improves device characteristics. In another embodiment on a chip having devices with halos adjacent diffusions, no halo diffusion is adjacent a rectifying contact diffusion of a lateral diode, significantly improving ideality of the diode and increasing breakdown voltage.

Abstract: A T-RAM array having a planar cell structure is presented. The T-RAM array includes n-MOS and p-MOS support devices which are fabricated by sharing process implant steps with T-RAM cells of the T-RAM array. A method is also presented for fabricating the T-RAM array having the planar cell structure. The method entails simultaneously fabricating a first portion of a T-RAM cell and the n-MOS support device; simultaneously fabricating a second portion of the T-RAM cell and the p-MOS support device; and finishing the fabrication of the T-RAM cell by interconnecting the T-RAM cell with the p-MOS and n-MOS support devices. The first portion of the T-RAM cell is a transfer gate and the second portion of the T-RAM cell is a gated-lateral thyristor storage element. Accordingly, process steps in fabricating the T-RAM cells are shared with process steps in fabricating the n-MOS and p-MOS support devices. The n-MOS and p-MOS support devices refer to sense amplifiers, wordline drivers, column and row decoders, etc.