Abstract: A multi-bit phase change memory cell including a stack of a plurality of conductive layers and a plurality of phase change material layers, each of the phase change material layers disposed between a corresponding pair of conductive layers and having electrical resistances that are different from one another.

Abstract: A novel asymmetric filter membrane, and process for making is disclosed in several exemplary versions. The membrane structure is physically robust and suitable for use in a wide variety of applications. The support membrane is may be comprised of material such as a porous silicon or a silicon oxide, and the separation membrane may be comprised of material such as a polymer, zeolite film, or silicon oxide. The process relies on steps adapted from the microelectronics industry.

Abstract: A carrier structure and method for fabricating a carrier structure with through-vias each having a conductive structure with an effective coefficient of thermal expansion which is less than or closely matched to that of the substrate, and having an effective elastic modulus value which is less than or closely matches that of the substrate. The conductive structure may include concentric via fill areas having differing materials disposed concentrically therein, a core of the substrate material surrounded by an annular ring of conductive material, a core of CTE-matched non-conductive material surrounded by an annular ring of conductive material, a conductive via having an inner void with low CTE, or a full fill of a conductive composite material such as a metal-ceramic paste which has been sintered or fused.

Abstract: Flared and non-flared metallized deep vias having aspect ratios of about 2 or greater are provided. Blind vias have been fabricated in silicon substrates up to a depth of about 300 microns, and flared through vias have been fabricated up to about 750 microns, the approximate thickness of a silicon substrate wafer, enabling the formation of electrical connections at either or both ends of a via. In spite of the depth and high aspect ratios attainable, the etched vias are completely filled with plated copper conductor, completing the formation of deep vias and allowing fuller use of both sides of the substrate.

Abstract: A photomask is formed by depositing an opaque layer on a transparent substrate. A resist is formed on the opaque layer and selectively patterned to expose the portions of the opaque layer that are to be etched out. During the dry etching step, the photomask is exposed to an etchant gas mixture which exhibit a selectivity equal to or higher than 1.2:1 between the opaque layer and the resist layer. Due to the higher selectivity of the gas mixture, a thinner resist film can be used, thereby increasing resolution and accuracy of the opaque layer pattern. Also, due to reduced susceptibility to both a macro-loading effect and a pattern density effect, overetching of the resist and underetching of the opaque layer are significantly reduced, thereby achieving improved etching uniformity and consequently improved CD uniformity.

Abstract: A photomask is formed by depositing an opaque layer on a transparent substrate. A resist is formed on the opaque layer and selectively patterned to expose the portions of the opaque layer that are to be etched out. During the dry etching step, the photomask is exposed to an etchant gas mixture which exhibit a selectivity equal to or higher than 1.2:1 between the opaque layer and the resist layer. Due to the higher selectivity of the gas mixture, a thinner resist film can be used, thereby increasing resolution and accuracy of the opaque layer pattern. Also, due to reduced susceptibility to both a macro-loading effect and a pattern density effect, overetching of the resist and underetching of the opaque layer are significantly reduced, thereby achieving improved etching uniformity and consequently improved CD uniformity.