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:
Methods and structures for forming strained-channel finFETs are described. Fin structures for finFETs may be formed in two epitaxial layers that are grown over a bulk substrate. A first thin epitaxial layer may be cut and used to impart strain to an adjacent channel region of the finFET via elastic relaxation. The structures exhibit a preferred design range for increasing induced strain and uniformity of the strain over the fin height.
Abstract:
A method of making a semiconductor device includes forming an intermediate structure including second semiconductor fin portions above a first semiconductor layer, and top first semiconductor fin portions extending from respective ones of the second semiconductor fin portions. The second semiconductor fin portions are selectively etchable with respect to the top first semiconductor fin portions. A dummy gate is on the intermediate structure. The second semiconductor fin portions are selectively etched to define bottom openings under respective ones of the top first semiconductor fin portions. The bottom openings are filled with a dielectric material.
Abstract:
An improved transistor with channel epitaxial silicon and methods for fabrication thereof. In one aspect, a method for fabricating a transistor includes: forming a gate stack structure on an epitaxial silicon region, a width dimension of the epitaxial silicon region approximating a width dimension of the gate stack structure; encapsulating the epitaxial silicon region under the gate stack structure with sacrificial spacers formed on both sides of the gate stack structure and the epitaxial silicon region; forming a channel of the transistor having a width dimension that approximates that of the epitaxial silicon region and the gate stack structure, the epitaxial silicon region and the gate stack structure formed on the channel of the transistor; removing the sacrificial spacers; and growing a raised epitaxial source and drain from the silicon substrate, with portions of the raised epitaxial source and drain in contact with the epitaxial silicon region.
Abstract:
Insulating layers can be formed over a semiconductor device region and etched in a manner that substantially reduces or prevents the amount of etching of the underlying channel region. A first insulating layer can be formed over a gate region and a semiconductor device region. A second insulating layer can be formed over the first insulating layer. A third insulating layer can be formed over the second insulating layer. A portion of the third insulating layer can be etched using a first etching process. A portion of the first and second insulating layers beneath the etched portion of the third insulating layer can be etched using at least a second etching process different from the first etching process.
Abstract:
The presence of a facet or a void in an epitaxially grown crystal indicates that crystal growth has been interrupted by defects or by certain material boundaries. Faceting can be suppressed during epitaxial growth of silicon compounds that form source and drain regions of strained silicon transistors. It has been observed that faceting can occur when epitaxial layers of certain silicon compounds are grown adjacent to an oxide boundary, but faceting does not occur when the epitaxial layer is grown adjacent to a silicon boundary or adjacent to a nitride boundary. Because epitaxial growth of silicon compounds is often necessary in the vicinity of isolation trenches that are filled with oxide, techniques for suppression of faceting in these areas are of particular interest. One such technique, presented herein, is to line the isolation trenches with SiN to provide a barrier between the oxide and the region in which epitaxial growth is intended.
Abstract:
A shallow trench is formed to extend into a handle substrate of a semiconductor-on-insulator (SOI) layer. A dielectric liner stack of a dielectric metal oxide layer and a silicon nitride layer is formed in the shallow trench, followed by deposition of a shallow trench isolation fill portion. The dielectric liner stack is removed from above a top surface of a top semiconductor portion, followed by removal of a silicon nitride pad layer and an upper vertical portion of the dielectric metal oxide layer. A divot laterally surrounding a stack of a top semiconductor portion and a buried insulator portion is filled with a silicon nitride portion. Gate structures and source/drain structures are subsequently formed. The silicon nitride portion or the dielectric metal oxide layer functions as a stopping layer during formation of source/drain contact via holes, thereby preventing electrical shorts between source/drain contact via structures and the handle substrate.
Abstract:
An insulating region for a semiconductor wafer and a method of forming same. The insulating region can include a tri-layer structure of silicon oxide, boron nitride and silicon oxide. The insulating region may be used to insulate a semiconductor device layer from an underlying bulk semiconductor substrate. The insulating region can be formed by coating the sides of a very thin cavity with silicon oxide, and filling the remainder of the cavity between the silicon oxide regions with boron nitride.
Abstract:
A multi-fin FINFET device may include a substrate and a plurality of semiconductor fins extending upwardly from the substrate and being spaced apart along the substrate. Each semiconductor fin may have opposing first and second ends and a medial portion therebetween, and outermost fins of the plurality of semiconductor fins may comprise an epitaxial growth barrier on outside surfaces thereof. The FINFET may further include at least one gate overlying the medial portions of the semiconductor fins, a plurality of raised epitaxial semiconductor source regions between the semiconductor fins adjacent the first ends thereof, and a plurality of raised epitaxial semiconductor drain regions between the semiconductor fins adjacent the second ends thereof.
Abstract:
Integrated circuits are disclosed in which the strain properties of adjacent pFETs and nFETs are independently adjustable. The pFETs include compressive-strained SiGe on a silicon substrate, while the nFETs include tensile-strained silicon on a strain-relaxed SiGe substrate. Adjacent n-type and p-type FinFETs are separated by electrically insulating regions formed by a damascene process. During formation of the insulating regions, the SiGe substrate supporting the n-type devices is permitted to relax elastically, thereby limiting defect formation in the crystal lattice of the SiGe substrate.