Abstract: Methods of planarizing structures formed on the surfaces of substrates and wafers are disclosed. The methods form a planarizing layer over the surface and the structures, or the locations where the structures are to be formed, such that the top surface of the layer has low areas between the locations of the structures, and such that the low areas lie substantially within a plane which is below the tops of the structures. A polish-stop layer is thee formed over the low areas of the planarizing layer, the polish-stop layer being more resistant to polishing than the planarizing layer and, preferably, the structures. The resulting surface is then polished. The polishing may be accomplished by, for example, standard mechanical polishing, and chemical-mechanical polishing.

Abstract: A method of fabricating a multilayer interconnected substrate is disclosed. In one embodiment, the method includes providing a structure having a dielectric substrate having a first substantially planar surface and an opposing second substantially planar surface. A first conductive layer is disposed on the first substantially planar surface of the dielectric substrate, and an interface is present between the first conductive layer and the dielectric substrate. A blind via site is formed in the structure, and through the dielectric substrate to the interface between the first conductive layer and the dielectric substrate. The blind via site is filled with a conductive material by an electrolytic plating process.

Abstract: A method of fabricating a substrate having a conductive layer on opposing sides, with the conductive layers interconnected by a conductive via. The inventive method uses a dielectric substrate having a conductive layer deposited or laminated onto one or both of the substrate's opposing surfaces. For the situation of a metal layer on one side of the substrate, a laser drill is used to drill blind vias through the dielectric, stopping at the substrate/conductive layer interface. An electrolytic plating process is used to fill the via by establishing an electrical connection to the conductive layer. A second conductive layer may be deposited or laminated to the other surface of the substrate. If the starting structure has a conductive layer on both sides of the substrate, the drill is controlled to bore through the upper conductive layer at a comparatively high power and then continue at a lower power through the substrate.

Abstract: Methods of planarizing structures formed on the surfaces of substrates and wafers are disclosed. The methods form a planarizing layer over the surface and the structures, or the locations where the structures are to be formed, such that the top surface of the layer has low areas between the locations of the structures, and such that the low areas lie substantially within a plane which is below the tops of the structures. A polish-stop layer is thee formed over the low areas of the planarizing layer, the polish-stop layer being more resistant to polishing than the planarizing layer and, preferably, the structures. The resulting surface is then polished. The polishing may be accomplished by, for example, standard mechanical polishing, and chemical-mechanical polishing.

Abstract: Several inventive features for increasing the yield of substrate capacitors are disclosed. The inventive features relating to selective placement of insulating layers and patches around selected areas of the capacitor's main dielectric layer. These insulating layers and defects prevent certain manufacturing processing steps from creating pin-hole defects in the main dielectric layer. The inventive features are suitable for any type of material for the main dielectric layer, and are particularly suited to anodized dielectric layers.

Abstract: Methods of etching polyamic acid layers and the like are disclosed. In exemplary embodiments of the present invention, the polymeric acid layer to be etched is alternatively exposed to etchant solutions (etchants) and rinse solutions, where the etchant solutions are of relatively moderate alkalinity and the rinse solutions have a lower pH than the etchant solutions. The present invention enables polymeric acid layers to be developed with standard basic etchants at relatively moderate concentrations and at room temperature with little, if any, corrosion to any underlying metal layers. The present invention enables the more reliable and cleaner spin-spray processing method to be employed, thereby significantly increasing yields and reducing overall processing costs. The present invention also enables the etching of thick layers of polymeric acid without the need for special treatments, such as exposure to highly concentrated etchant solutions or high temperature processing conditions.

Abstract: A method for plating conductive material in through apertures and blind apertures of a substrate which has a conductive material on its upper and lower surfaces. In a typical configuration for plating a via, there is a first region of conductive material adjacent to, but outside of, the aperture which forms the via and a second region of conductive material inside of the aperture. The second conductive region is selected to be the cathode of the plating process. The structure is placed in a plating bath, a first potential is applied to the first region of conductive material, and a second potential is applied to the second region of conductive material, with the second potential being different from the first potential. Under these conditions, material will plate onto the second region of conductive material to fill the aperture.

Abstract: A method of fabricating a multi-layer interconnected substrate structure. The inventive method includes forming a multi-layer structure from multiple, pre-fabricated power and/or signal substrates which are laminated together. A drill is then used to form a via through the surface of a ring-type pad down to a desired depth in the multi-layer structure. The via hole is cleaned and then filled with a conductive material. The via so formed between two or more substrates is self-aligned by using the ring pad(s). This contributes to an increased signal routing density compared to conventional methods.

Abstract: An interposer substrate for mounting an integrated circuit chip to a substrate, and method of making the same, are shown. The interposer substrate comprises power supply paths and controlled impedance signal paths that are substantially isolated from each other. Power supply is routed through rigid segments and signals are routed through a thin film flexible connector that runs from the upper surface of the interposer substrate to the lower surface. Bypass capacitance is incorporated into the interposer substrate and connected to the power supply so that it is positioned very close to the integrated circuit chip. The interposer may be fabricated by forming a multilayered thin film structure including the signal paths over a rigid substrate having vias formed therein, removing the central portion of the substrate leaving the two end segments, and folding and joining the end segments such that the vias are connected.

Abstract: An interposer for providing power, ground, and signal connections between an integrated circuit chip or chips and a substrate. The interposer includes a signal core and external power/ground connection wrap. The two sections may be fabricated and tested separately, then joined together using z-connection technology. The signal core is a dielectric film with patterned metal on both sides. The two metal layers are interconnected by a through via or post process. The power/ground wrap includes an upper substrate positioned above the signal core and a lower substrate positioned below the signal core. The upper and lower substrates of the power/ground wrap are formed from a dielectric film having a patterned metal layer on both sides connected by a through via or post process. The upper power/ground wrap substrate, signal core, and lower power/ground substrate are interconnected as desired using z-connection technology (e.g., solder or conductive ink).

Abstract: Methods of forming patterns in photo-sensitive resist layers with high aspect ratio features are described. The photosensitive layer is patterned exposed to actinic radiation and thereafter developed. For high aspect ratio patterns, the inventors have often observed a residue of resist material at the bottom of such features, and that this residue interferes with subsequent processing, such as filling the pattern with metal by a plating operation. To remove this residue, the patterned locations of the resist are exposed to a low dose of low-energy electron beam radiation, preferably having energy of less than 6 KeV and dosage of less than 200 .mu.C/cm.sup.2. After the electron beam exposure, the aperture is again exposed to a developer solution, which may be of the same composition as the developer initially used to develop the patterns.

Abstract: An interconnecting post for mounting a microelectronic device such as an integral circuit chip is fabricated with generally uniform cross-section, by forming a first layer of positive photoresist on a substrate, soft-baking that first layer and exposing it for a short time with a wide-apertured mask or simply a UV blank flood exposure. Without developing the first layer, a second layer of positive resist is then applied over the first layer, soft-baked, and then exposed with a narrow-apertured mask. During the soft-baking of the second layer, some of its activator in the photoresist compound diffuses into the exposed portion of the first layer and modifies its solubility in such a way that, when the layers are subsequently developed, the developer partially undercuts the unexposed portion of the first layer to form in the photoresist an opening of generally uniform cross-section. This opening can then be filled by plating to produce a strong, integral interconnect post.

Abstract: Methods of planarizing structures formed on the surfaces of substrates and wafers are disclosed. The methods form a planarizing layer over the surface and the structures, or the locations where the structures are to be formed, such that the top surface of the layer has low areas between the locations of the structures, and such that the low areas lie substantially within a plane which is below the tops of the structures. A polish-stop layer is then formed over the low areas of the planarizing layer, the polish-stop layer being more resistant to polishing than the planarizing layer and, preferably, the structures. The resulting surface is then polished. The polishing may be accomplished by, for example, standard mechanical polishing, and chemical-mechanical polishing.

Abstract: Methods of wet etching through a silicon substrate using composite etch-stop layers are disclosed. In one embodiment, the composite etch stop comprises a layer of silicon dioxide and a layer of polyimide.

Abstract: An interposer substrate for mounting an integrated circuit chip to a substrate, and method of making the same, are shown. The interposer substrate comprises power supply paths and controlled impedance signal paths that are substantially isolated from each other. Power supply is routed though rigid segments and signals are routed though a thin film flexible connector that runs from the upper surface of the interposer substrate to the lower surface. Bypass capacitance is incorporated into the interposer substrate and connected to the power supply so that it is positioned very close to the integrated circuit chip. The interposer may be fabricated by forming a multilayered thin film structure including the signal paths over a rigid substrate having vias formed therein, removing the central portion of the substrate leaving the two end segments, and folding and joining the end segments such that the vias are connected.

Abstract: Methods of forming patterns in photo-sensitive resist layers with high aspect ratio features are described. The photosensitive layer is patterned exposed to actinic radiation and thereafter developed. For high aspect ratio patterns, the inventors have often observed a residue of resist material at the bottom of such features, and that this residue interferes with subsequent processing, such as filling the pattern with metal by a plating operation. To remove this residue, the patterned locations of the resist are exposed to a low dose of low-energy electron beam radiation, preferably having energy of less than 6 KeV and dosage of less than 200 .mu.C/cm.sup.2. After the electron beam exposure, the aperture is again exposed to a developer solution, which may be of the same composition as the developer initially used to develop the patterns.

Abstract: A multichip module substrate for use in a three-dimensional multichip module, and methods of making the same, are disclosed. The substrate comprises a thin film structure, for routing signals to and from integrated circuit chips, formed over a rigid support base. Apertures are formed in the support base exposing the underside of the thin film structure, thereby allowing high density connectors to be mounted on both surfaces of the thin film structure, greatly enhancing the ability to communicate signals between adjacent substrates in the chip module. This avoids the need to route the signals either through the rigid support base or to the edges of the thin film structure. Power and ground, which do not require a high connection density, are routed in low impedance paths through the support base. Preferably, the thin film structure is made of alternating layers of patterned metal, such as copper, and a low dielectric organic polymer, such as a polyimide.

Abstract: Methods of forming high-aspect ratio blind apertures and thereafter filling the apertures with a plating solution are disclosed. A layer of photosensitive material is pattern exposed to actinic radiation to define the apertures, and thereafter exposed to aqueous developer solution. The apertures are then rinsed with water and thereafter exposed to plating solution without drying the aperture of water or developer solution. This is contrary to conventional practice where photoresist layers are dried, and usually post-baked after the development step in order to improve dimensional integrity and reduce swelling of the photoresist material.

Abstract: An interconnecting post for mounting a microelectronic device such as an integral circuit chip is fabricated with generally uniform cross-section, by forming a first layer of positive photoresist on a substrate, soft-baking that first layer and exposing it for a short time with a wide-apertured mask or simply a UV blank flood exposure. Without developing the first layer, a second layer of positive resist is then applied over the first layer, soft-baked, and then exposed with a narrow-apertured mask. During the soft-baking of the second layer, some of its activator in the photoresist compound diffuses into the exposed portion of the first layer and modifies its solubility in such a way that, when the layers are subsequently developed, the developer partially undercuts the unexposed portion of the first layer to form in the photoresist an opening of generally uniform cross-section. This opening can then be filled by plating to produce a strong, integral interconnect post.

Abstract: Methods for pretreating patterned masks layers, such as photoresist masks, with electron-beam radiation for use in high temperature processes are disclosed. The electron-beam exposure deactivates compounds within the mask material which would ordinarily decompose and produce gasses within the photoresist layer. The gasses cause blistering in the untreated photoresist layer, which in turn degrades the dimensional integrity of the untreated layer.