Abstract: A method is disclosed for producing coplanar metal/insulator films on a substrate according to a chem-mech polishing technique. In one example, a substrate having a patterned insulating layer of dielectric material thereon, is coated with a layer of metal. The substrate is then placed in a parallel polisher and the metal is removed elsewhere except in the holes where it is left intact. This is made possible through the use of an improved selective slurry which removes the metal much faster than the dielectric material. The insulating layer may then be used as an automatic etch stop barrier.In a second example a substrate having a patterned metallic layer is coated with an insulating layer and then subjected to chem-mech polishing. The structure is coplanarized by the chem-mech removal of the insulating material from the high points of the structure at a faster rate than from the lower points. Optional etch stop layers also may be used.

Abstract: Deep dielectric isolation zones in a substrate are achieved by forming trenches using reactive ion etching. A glass having a coefficient of thermal expansion closely matching that of the substrate is deposited onto the trench to entirely or partially fill the trench. Deposition can be by sedimentation, centrifugation or spin-on techniques. The structure is then fired until the glass particles fuse into a continuous glass layer and final smoothing if necessary can be accomplished.

Abstract: A method is described for forming the recessed dielectric isolation in a silicon substrate involves first forming trenches which may be less than about 1 micron in depth in areas of one principal surface of the silicon substrate where isolation is desired. Where, for example, an NPN bipolar transistor structure is planned to be formed it is usually necessary to have a P+ region underneath the recessed dielectric isolation to allow full isolation between the various bipolar transistor devices. A PNP transistor uses an N+ region underneath the isolation. Where a field effect transistor is planned a channel stop can be substituted for the P+ region. Under the circumstance of bipolar devices, the P+ region is formed in the substrate prior to the deposition of an epitaxial layer thereover. The trench formation is caused to be formed through the epitaxial layer and into the P+ regions therein. The surface of the trenches are then oxidized in an oxidizing ambient to form a silicon dioxide layer thereon.

Abstract: A method is given for forming a planarized integrated circuit structure just prior to the formation of metallurgy interconnection lines on the integrated circuit. The method begins with the integrated circuit intermediate product having devices formed therein but before interconnection metallurgy has been formed on the principal surface of the product. A glass layer is deposited in a non-conformal way onto the principal surface of the integrated circuit. The glass is chosen to have a thermal coefficient of expansion that approximates that silicon and has a softening temperature of less than about 1200.degree. C. The thermal coefficient of expansion approximates that of silicon to reduce stress problems in the integrated circuit structure. The relatively low softening temperature is required for the next step of heating the structure to cause the flow of glass on the surface of the integrated circuit product to fill in the irregularities therein and to thereby planarize the integrated circuit surface.

Abstract: A method of making a metal-oxide-semiconductor device is disclosed. A thin silicon dioxide insulating layer is formed on the surface of a planar silicon wafer. A first layer of intrinsic polycrystalline silicon is deposited over the dioxide layer, and a second layer of doped polycrystalline silicon is deposited over the intrinsic layer, thereby forming the gate. Subsequent hot processing steps result in diffusion of a portion of the dopant from the doped polycrystalline layer into and throughout the intrinsic layer so as to dope the latter. A metal contact layer is then deposited onto the gate and in superimposed vertical alignment with respect to the thin silicon dioxide insulating layer. The intrinsic nature of the first polycrystalline layer reduces grain growth and void formation in the polycrystalline silicon and thereby prevents the silicon dioxide from being attacked by hydrofluoric acid seeping through voids in the polycrystalline layer during subsequent processing.

Abstract: A method of making a metal-oxide-semiconductor device is disclosed. A thin silicon dioxide insulating layer is formed on the surface of a planar silicon wafer. A first layer of intrinsic polycrystalline silicon is deposited over the dioxide layer, and a second layer of doped polycrystalline silicon is deposited over the intrinsic layer, thereby forming the gate. Subsequent hot processing steps result in diffusion of a portion of the dopant from the doped polycrystalline layer into and throughout the intrinsic layer so as to dope the latter. A metal contact layer is then deposited onto the gate and in superimposed vertical alignment with respect to the thin silicon dioxide insulating layer. The instrinsic nature of the first polycrystalline layer reduces grain growth and void formation in the polycrystalline silicon and thereby prevents the silicon dioxide from being attacked by hydrofluoric acid seeping through voids in the polycrystalline layer during subsequent processing.