摘要:
The invention described is an improved dielectric material formed as a film on the surface of a substrate by adding lead to an original perovskite material having an original critical grain size to form a lead enhanced perovskite material, then forming a layer of the lead enhanced perovskite material having an average grain size less than the original critical grain size whereby the dielectric constant of the layer is substantially greater than the dielectric constant of the original perovskite material with an average grain size similar to the average grain size of the layer. The critical grain size, as used herein, means the largest grain size such that the dielectric constant starts to rapidly decrease with decreasing grain sizes. Preferably, the lead enhanced perovskite material is further doped with one or more acceptor dopants whereby the resistivity is substantially increased and/or the loss tangent is substantially decreased. Preferably, the original perovskite material has a chemical composition ABO.sub.3, where A is one or more monovalent, divalent or trivalent elements, and B is one or more pentavalent, tetravalent, trivalent or divalent elements.
摘要:
The invention forms improved ferroelectric (or pyroelectric) material by doping an intrinsic perovskite material having an intrinsic ferroelectric (or pyroelectric) critical grain size with one or more donor dopants, then forming a layer of the donor doped perovskite material having an average grain size less than the intrinsic ferroelectric (or pyroelectric) critical gran size whereby the remanent polarization (or pyroelectric figure of merit) of the layer is substantially greater than the remanent polarization (or pyroelectric figure of merit) of the intrinsic perovskite material with an average grain size similar to the average grain size of the layer. The critical ferroelectric (or pyroelectric) grain size, as used herein, means the largest grain size such that the remanent polarization (or pyroelectric figure of merit) starts to rapidly decrease with decreasing grain sizes. Preferably, the donor doped perovskite material is further doped with one or more acceptor dopants to form a donor acceptor doped perovskite material whereby the resistivity is substantially increased. Preferably, the intrinsic perovskite material has a chemical composition AB03, where A is one or more monovalent, divalent or trivalent elements, and B is one or more pentavalent, tetravalent, trivalent or divalent elements. Structures containing an improved ferroelectric (or pyroelectric) material include a layer of donor doped perovskite material with average grain size less than the intrinsic ferroelectric (or pyroelectric) critical grain size formed on the surface of a substrate. Other structures include such a layer of donor doped material interposed between two electrically conducting layers.
摘要:
The invention described is a method of forming an improved dielectric material by adding lead to an original perovskite material having an original critical grain size to form a lead enhanced perovskite material, then forming a layer of the lead enhanced perovskite material having an average grain size less than the original critical grain size whereby the dielectric constant of the layer is substantially greater than the dielectric constant of the original perovskite material with an average grain size similar to the average grain size of the layer. The critical grain size, as used herein, means the largest grain size such that the dielectric constant starts to rapidly decrease with decreasing grain sizes. Preferably, the lead enhanced perovskite material is further doped with one or more acceptor dopants whereby the resistivity is substantially increased and/or the loss tangent is substantially decreased. Preferably, the original perovskite material has a chemical composition ABO3, where A is one or more monovalent, divalent or trivalent elements, and B is one or more pentavalent, tetravalent, trivalent or divalent elements.
摘要:
An etching process is provided using electromagnetic radiation and a selected etchant (52) to selectively remove various types of materials (53) from a substrate (48). Contacts (49, 56, 64) may be formed to shield the masked regions (51) of the substrate (48) having an attached coating (20) during irradiation of the unmasked regions (53) of the substrate (48). The unmasked regions (53) are then exposed to an etchant (52) and irradiated to substantially increase their reactivity with the etchant (52) such that the etchant (52) etches the unmasked regions (53) substantially faster than the masked regions (51) and the contacts (49, 56, 64).
摘要:
A preferred embodiment of this invention comprises a perovskite-seed layer (e.g. calcium ruthenate 40) between a conductive oxide layer (e.g. ruthenium oxide 36) and a perovskite dielectric material (e.g. barium strontium titanate 42), wherein the perovskite-seed layer and the conductive oxide layer each comprise the same metal. The metal should be conductive in its metallic state and should remain conductive when partially or fully oxidized. Generally, the perovskite-seed layer has a perovskite or perovskite-like crystal structure and lattice parameters which are similar to the perovskite dielectric layer formed thereon. At a given deposition temperature, the crystal quality and other properties of the perovskite dielectric will generally be enhanced by depositing it on a surface having a similar crystal structure. Undesirable crystal structure formation will generally be minimized and lower processing temperatures may be used to deposit the perovskite dielectric layer. Another benefit of this electrode system is that the perovskite-seed layer should do little or no reduction of the perovskite dielectric layer.
摘要:
A semiconductor device (10) is illustrated, which is formed on an active region (14) of a semiconductor substrate (12). Device (10) comprises a conductive plug (20) and a barrier layer (22) formed in an opening in an interlevel isolation layer (18). An inner electrode (24) is caused to adhere to the interlevel isolation layer (18) through the use of an adhesion layer (26). High-dielectric-constant layer (28) and an outer electrode (30) are formed outwardly from inner electrode (24).
摘要:
A preferred embodiment of this invention comprises a thin unreactive film (e.g. platinum 36) contacting a high-dielectric-constant material (e.g. barium strontium titanate 38) to an electrode. The thin unreactive film provides a stable conductive interface between the high-dielectric-constant material layer and the electrode base (e.g. palladium 34). As opposed to a standard thin-film layer, the thin unreactive film is generally less than 50 nm thick, preferably less than 35 nm thick, more preferably between 5 nm and 25 nm thick, and most preferably between 10 nm and 20 nm thick. A thin unreactive film can benefit from the advantages of the materials used while avoiding or minimizing many of their disadvantages. A thin unreactive film would generally be substantially less expensive than a standard thin-film layer since much less material can be used while not significantly affecting the surface area of the electrode in contact with the HDC material. These structures may also be used for multilayer capacitors and other thin-film ferroelectric devices such as pyroelectric materials, non-volatile memories, thin-film piezoelectric and thin-film electro-optic oxides.
摘要:
A preferred embodiment of this invention comprises a first thin dielectric buffer layer of a first leakage-current-density material (e.g. strontium titanate 32) with a first moderate-dielectric-constant, a high-dielectric-constant layer of a second leakage-current-density material (e.g. barium strontium titanate 34) overlaying the first thin dielectric buffer layer, and a second thin dielectric buffer layer of a third leakage-current-density material (e.g. strontium titanate 36) with a second moderate-dielectric-constant overlaying the high-dielectric-constant layer, wherein the first and third leakage-current-density materials have substantially lower leakage-current-densities than the second leakage-current-density material. The first and second thin moderate-dielectric-constant buffer layers (e.g. strontium titanate 32, 36) substantially limit the leakage-current-density of the structure, with only modest degradation of the dielectric constant of the structure. The possibly lower dielectric constant of the structure is generally compensated for by the reduced leakage current of the structure. The additional layers generally require only minor modifications of existing processes, since the same processes that are used for the high-dielectric-constant oxide can generally be used for the low leakage-current-density dielectric. These structures may also be used for multilayer capacitors and other thin-film ferroelectric devices such as pyroelectric materials, non-volatile memories, thin-film piezoelectric and thin-film electro-optic oxides.
摘要:
A thermal sensor (36, 84, 114) comprising a thermal assembly (44, 88, 118) and a signal flowpath (46, 90, 120). The thermal assembly (44, 88, 118) may comprise a thermally sensitive element (50) and a pair of electrodes (52, 54). The thermally sensitive element (50) may generate a signal representative of an amount of thermal radiation incident to the thermally sensitive element (50). The electrodes (52, 54) may collect the signal generated by the thermally sensitive element (50). The signal flowpath (46, 90, 120) may transmit the signal collected by the electrodes (52, 54) to the substrate (34, 82, 112). The signal flowpath (46, 90, 120) may comprise a pair of arms (56, 58, 92, 122) each extending from an electrode (52, 54) and be connected to the substrate (34, 82, 112). The arms (56, 58, 92, 122) may support the thermal assembly (44, 88, 118) in spaced relation with the substrate (34, 82, 112). The arms (56, 58, 92, 122) may be formed of a thermally insulating material.
摘要:
An array of thermal sensitive elements (16) may be formed from a pyroelectric substrate (46) having an infrared absorber and common electrode assembly (18) attached thereto. A first layer of electrically conductive contacts (60) is formed to define in part masked (61) and unmasked (68) regions of the substrate (46). A second layer of electrically conductive contacts (62) may be formed on the first layer of contacts (60). A mask layer (66) is formed to encapsulate the exposed portions of the second layer of contacts (62). The unmasked regions (68) are exposed to an etchant (70) and irradiated to substantially increase the reactivity between the unmasked regions (68) and the etchant (70) such that during irradiation, the etchant (70) removes the unmasked regions (68) substantially faster than the first layer of contacts (60) and the mask layer (66).