Abstract: A cube package of stacked silicon semiconductor chips. To accommodate cube packaging, a metal transfer layer is added over the passivated chip face to bring all of the surface electrical contacts to a common chip edge. The metal transfer layer is insulated from the chip face and from the adjacent chip in the stack by polymer layers having a low dielectric constant, and a thermal expansion coefficient matching that of the stacked chips. An adhesive polymer layer is added to strengthen the bond between the first polymer layers and the adjacent chip in the stack, by deposition of the adhesive layer and partial cure at the wafer level, and then full cure when the chips are stacked together to form the cube.

Abstract: A metallization composite comprises a refractory metal, nickel, and copper. The refractory metal is preferably titanium (Ti), but other suitable refractory metals such as zirconium and hafnium can also be utilized. An additional optional layer of gold can overlie the copper. The metallization composite is used to connect a solder contact to a semiconductor substrate.

Abstract: A gray level mask suitable for photolithography is constructed of a transparent glass substrate which supports plural levels of materials having different optical transmissivities. In the case of a mask employing only two of these levels, one level may be constructed of a glass made partially transmissive by substitution of silver ions in place of metal ions of alkali metal silicates employed in the construction of the glass. The second layer may be made opaque by construction of the layer of a metal such as chromium. The mask is fabricated with the aid of a photoresist structure which is etched in specific regions by photolithographic masking to enable selective etching of exposed regions of the level of materials of differing optical transmissivities. Various etches are employed for selective etching of the photoresist, the metal of one of the layers, and the glass of the other of the layers.

Abstract: A fabrication method and resultant three-dimensional multichip package having a densely stacked array of semiconductor chips interconnected at least partially by means of a plurality of metallized trenches are disclosed. The fabrication method includes providing an integrated circuit chip having high aspect ratio metallized trenches therein extending from a first surface to a second surface thereof. An etch stop layer is provided proximate the termination position of the metallized trenches with the semiconductor substrate. Next the integrated circuit device is affixed to a carrier such that the surface of the supporting substrate is exposed and substrate is thinned from the integrated circuit device until exposing at least some of the plurality of metallized trenches therein. Electrical contact can thus be made to the active layer of the integrated circuit chip via the exposed metallized trenches. Specific details of the fabrication method and the resultant multichip package are set forth.

Abstract: A gray level mask suitable for photolithography is constructed of a transparent glass substrate which supports plural levels of materials having different optical transmissivities. In the case of a mask employing only two of these levels, one level may be constructed of a glass made partially transmissive by substitution of silver ions in place of metal ions of alkali metal silicates employed in the construction of the glass. The second layer may be made opaque by construction of the layer of a metal such as chromium. The mask is fabricated with the aid of a photoresist structure which is etched in specific regions by photolithographic masking to enable selective etching of exposed regions of the level of materials of differing optical transmissivities. Various etches are employed for selective etching of the photoresist, the metal of one of the layers, and the glass of the other of the layers.

Abstract: A fabrication method and resultant three-dimensional multichip package having a densely stacked array of semiconductor chips interconnected at least partially by means of a plurality of metallized trenches are disclosed. The fabrication method includes providing an integrated circuit chip having high aspect ratio metallized trenches therein extending from a first surface to a second surface thereof. An etch stop layer is provided proximate the termination position of the metallized trenches with the semiconductor substrate. Next the integrated circuit device is affixed to a carrier such that the surface of the supporting substrate is exposed and substrate is thinned from the integrated circuit device until exposing at least some of the plurality of metallized trenches therein. Electrical contact can thus be made to the active layer of the integrated circuit chip via the exposed metallized trenches. Specific details of the fabrication method and the resultant multichip package are set forth.

Abstract: Disclosed is a process for passivating a metal surface in a metal/polyimide structure, such as a polyimide layer on a semiconductor substrate containing a pattern of metallization. The process involves the formation of an intermediate layer of a silsesquioxane polymer between the polyimide layer and the substrate. The silsesquioxane layer passivates the metal, to inhibit interaction between the metal surface and the polyimide precursor material used in forming the polyimide, to provide a moisture-resistant and oxidation-resistant interface.

Abstract: A sequence of masking steps reduces the amount of transference of a workpiece among work stations and reduces certain tolerances required for mask alignment in the construction of integrated circuits, and a gray level mask suitable for photolithography. In the integrated circuit, masking layers are developed directly in a wafer for delineating vertical and horizontal portions of an electrically conductive path. The mask is constructed of a transparent glass substrate which supports plural levels of materials having different optical transmissivities. In the case of a mask employing only two of these levels, one level may be constructed of a glass made partially transmissive by substitution of silver ions in place of metal ions of alkali metal silicates employed in the construction of the glass. The second layer may be made opaque by construction of the layer of a metal such as chromium.

Abstract: Disclosed is a process for passivating a metal surface in a metal/polyimide structure, such as a polyimide layer on a semiconductor substrate containing a pattern of metallization. The process invovles the formation of an intermediate layer of a silsesquioxane polymer between the polyimide layer and the substrate. The silsesquioxane layer passivates the metal, to inhibit interaction between the metal surface and the polyimide precursor material used in forming the polyimide, to provide a moisture-resistant and oxidation-resistant interface.