Abstract:
A method of producing deep submicron vias is described in which a metal blanket layer is formed on a premetal dielectric and patterned to form line elements. An intermetal dielectric is then deposited over the patterned metal and chemically mechanically polished down to the top of the line elements. A second metal blanket layer is then deposited and patterned to form via studs. An intermetal dielectric is also deposited over the patterned metal via studs and polished down to the tops of the studs. The process is repeated until a multilevel integrated circuit is formed.
Abstract:
In one aspect, the present invention comprises an electrostatic discharge (ESD) protection circuit comprising a plurality of input circuits in which each input circuit comprises a first PMOS and a first NMOS transistor connected in series between a power supply and ground and first and second inverters connected to the gates of the first PMOS and NMOS transistors. Each inverter connected to the gate of the first NMOS transistor comprises a second NMOS transistor connected between that gate and ground and the ratio of the width of the gate of the second NMOS transistor to the width of the gate of the first NMOS transistor of each of the input circuits is substantially the same. In another aspect of the invention, a multi-fingered gate transistor is formed in a first well of one conductivity type that is surrounded by a second well of the same conductivity type from which it is separated by a shallow trench isolation and a portion of the substrate. The second well is used as a tap for the first well with a significant increase in the resistance of the substrate current path. A process for forming this structure is a further aspect of the invention.
Abstract:
An apparatus for chemical-mechanical planarization (CMP) of semiconductor wafers that allows independent micro-control of each spindle for tailored CMP performance. The present invention provides, in one embodiment, a CMP tool that includes a stationary bridge that houses a rack and pinion assembly. The rack and pinion assembly is coupled to a plurality of motor assemblies each of which is coupled to rotate a spindle. Significantly, movements of the spindles across are individually and independently controlled by the rack and pinion assembly. An advantage of the present independent spindle motion design allows optimization of the CMP process for each spindle and enables more accurate prediction of the effect of translation on CMP performance. Independent rotation and downforce capability of the present invention provides additional flexibility in terms of tuning polish rates and uniformity. Another advantage of the present invention is that a more compact enclosure for wafer isolation can be achieved.
Abstract:
In modern sub-micron technologies with aggressive design rules, it is not always possible to have complete overlap of conductive lines with underlying vias. A process for manufacturing a semiconductor device having metal interconnects reduces or eliminates the recessing of metal in the vias, particularly when the metal in the vias is aluminum or an aluminum alloy. By manipulating the etch chemistry so that the etch rates of the aluminum alloy, the surrounding barrier metals, and the dielectric are comparable, it is possible to perform the metal over etch without forming voids in the exposed portion of the via. By eliminating the voids, thinning of the vias due to the presence of recesses is minimized, and electrical connections are less susceptible to electromigration. Consequently, device yield and reliability are increased.
Abstract:
A process for manufacturing a semiconductor device having metal interconnects reduces or eliminates the recessing of metal in the vias, particularly when the metal in the vias is aluminum or an aluminum alloy. The process includes forming a via in a device layer of the semiconductor device. A barrier layer is formed over the device layer and a metal layer is formed over the barrier layer. The metal layer also fills the via to form a via structure. A portion of the metal layer is then removed and a remaining portion of the metal layer forms a conductive structure having a sidewall extending from a surface of the barrier layer. A spacer is formed along the sidewall of the conductive structure and a portion of the barrier layer is removed using the spacer to protect the via structure adjacent the surface of the device layer. In particular, the spacer protects a portion of the via structure that does not overlap with the conductive structure.