Abstract:
Elongated fins of a first semiconductor material are insulated from and formed over an underlying substrate layer (of either SOI or bulk type). Elongated gates of a second semiconductor material are then formed to cross over the elongated fins at channel regions, and the gate side walls are covered by sidewall spacers. A protective material is provided to cover the underlying substrate layer and define sidewall spacers on side walls of the elongated fins between the elongated gates. The first semiconductor material and insulating material of the elongated fins located between the protective material sidewall spacers (but not under the elongated gates) is removed to form trenches aligned with the channel regions. Additional semiconductor material is then epitaxially grown inside each trench between the elongated gates to form source-drain regions adjacent the channel regions formed by the elongated fins of the first semiconductor material located under the elongated gates.
Abstract:
On a substrate formed of a first semiconductor material, a first overlying layer formed of a second semiconductor material is deposited. A second overlying layer formed of a third semiconductor material is deposited over the first overlying layer. The first and second overlying layers are patterned to define fins, wherein each fin includes a first region formed of the third material over a second region formed of the second material. An oxide material fills the space between the fins. A thermal oxidation is then performed to convert the second region to a material insulating the first region formed of the third material from the substrate. As an optional step, the second region formed of the second material is horizontally thinned before the oxide material is deposited and the thermal oxidation is performed. Once the fins are formed and insulated from the substrate, conventional FinFET fabrication is performed.
Abstract:
A method for forming a complementary metal oxide semiconductor (CMOS) semiconductor device includes providing a stressed silicon-on-insulator (sSOI) wafer comprising a stressed semiconductor layer having first and second laterally adjacent stressed semiconductor portions. The first stressed semiconductor portion defines a first active region. The second stressed semiconductor portion is replaced with an unstressed semiconductor portion. The unstressed semiconductor portion includes a first semiconductor material. The method further includes driving a second semiconductor material into the first semiconductor material of the unstressed semiconductor portion defining a second active region.
Abstract:
Channel-to-substrate leakage in a FinFET device is prevented by inserting an insulating layer between the semiconducting channel (fin) and the substrate during fabrication of the device. Similarly, source/drain-to-substrate leakage in a FinFET device is prevented by isolating the source/drain regions from the substrate by inserting an insulating layer between the source/drain regions and the substrate. Forming such an insulating layer isolates the conduction path from the substrate both physically and electrically, thus preventing current leakage. In an array of semiconducting fins made up of a multi-layer stack, the bottom material is removed, thus yielding a fin array that is suspended above the silicon surface. A resulting gap underneath the remaining top fin material is then filled with oxide to better support the fins and to isolate the array of fins from the substrate.
Abstract:
Silicon germanium regions are formed adjacent gates electrodes over both n-type and p-type regions in an integrated circuit. A hard mask patterned by lithography then protects structures over the p-type region while the silicon germanium is selectively removed from over the n-type region, even under remnants of the hard mask on sidewall spacers on the gate electrode. Silicon germanium carbon is epitaxially grown adjacent the gate electrode in place of the removed silicon germanium, and source/drain extension implants are performed prior to removal of the remaining hard mask over the p-type region structures.
Abstract:
A SOI substrate layer formed of a silicon semiconductor material includes adjacent first and second regions. A portion of the silicon substrate layer in the second region is removed such that the second region retains a bottom portion made of the silicon semiconductor material. An epitaxial growth of a silicon-germanium semiconductor material is made to cover the bottom portion. Germanium is then driven from the epitaxially grown silicon-germanium material into the bottom portion to convert the bottom portion to silicon-germanium. Further silicon-germanium growth is performed to define a silicon-germanium region in the second region adjacent the silicon region in the first region. The silicon region is patterned to define a first fin structure of a FinFET of a first (for example, n-channel) conductivity type. The silicon-germanium region is also patterned to define a second fin structure of a FinFET of a second (for example, p-channel) conductivity type.
Abstract:
On a substrate formed of a first semiconductor layer, an insulating layer and a second semiconductor layer, a silicon oxide pad layer and a silicon nitride pad layer are deposited and patterned to define a mask. The mask is used to open a trench through the first semiconductor layer and insulating layer and into the second semiconductor layer. A dual liner of silicon dioxide and silicon nitride is conformally deposited within the trench. The trench is filled with silicon dioxide. A hydrofluoric acid etch removes the silicon nitride pad layer along with a portion of the conformal silicon nitride liner. A hot phosphoric acid etch removes the silicon oxide pad layer, a portion of the silicon oxide filling the trench and a portion of the conformal silicon nitride liner. The dual liner protects against substrate etch through at an edge of the trench between the first and second semiconductor layers.
Abstract:
An improved transistor with channel epitaxial silicon. In one aspect, a method of fabrication includes: forming a gate stack structure on an epitaxial silicon region disposed on a substrate, a width dimension of the epitaxial silicon region approximating a width dimension of the gate stack structure; and growing a raised epitaxial source and drain from the substrate, the raised epitaxial source and drain in contact with the epitaxial silicon region and the gate stack structure. For a SRAM device, further: removing an epitaxial layer in contact with the silicon substrate and the raised source and drain and to which the epitaxial silicon region is coupled leaving a space above the silicon substrate and under the raised epitaxial source and drain; and filling the space with an insulating layer and isolating the raised epitaxial source and drain and a channel of the transistor from the silicon substrate.
Abstract:
A method for making a semiconductor device includes forming at least one gate stack on a layer comprising a first semiconductor material and etching source and drain recesses adjacent the at least one gate stack. The method further includes shaping the source and drain recesses to have a vertical side extending upwardly from a bottom to an inclined extension adjacent the at least one gate stack.
Abstract:
A memory device may include a semiconductor substrate, and a memory transistor in the semiconductor substrate. The memory transistor may include source and drain regions in the semiconductor substrate and a channel region therebetween, and a gate stack. The gate stack may include a first dielectric layer over the channel region, a first diffusion barrier layer over the first dielectric layer, a first electrically conductive layer over the first diffusion barrier layer, a second dielectric layer over the first electrically conductive layer, a second diffusion barrier layer over the second dielectric layer, and a second electrically conductive layer over the second diffusion barrier layer. The first and second dielectric layers may include different dielectric materials, and the first diffusion barrier layer may be thinner than the second diffusion barrier layer.