摘要:
An improved lift-off process for multilevel metal structure in the fabrication of integrated circuits by employing lift-off layer formed from polymers which undergo clean depolymerization under the influence of heat or radiation and allow rapid and residue-free release of an "expendable mask". An embedded interconnection metallurgy system is formed by application of the lift-off layer of this invention over a cured polymer film or on an oxygen RIE barrier layer previously deposited on organic or inorganic substrate, followed by another barrier over which is then coated a radiation sensitive resist layer. After definition of the desired resist pattern by imagewise exposure and development, the image is replicated into the barrier by sputter etching in a fluorine containing ambient and subsequently into the base layer down to the substrate by oxygen reactive ion etching which is followed by blanket metal evaporation and finally the lift-off by brief heat treatment at the depolymerization temperature of the lift-off layer, and brief solvent soak.
摘要:
Die Maske enthält eine dünne P+-dotierte Siliciumschicht (1) mit durchgehenden, dem Maskenmuster angepaßten Löchern (21), ein dies& Schicht (1) unterstützendes Gitter (2) aus Siliciumrippen, mindestens auf ihrer von dem Gitter (2) abgewandten Seite eine Schicht (5, 6), welche mindestens so dick ist, daß das Implantieren von lonen in die Siliciumschicht verhindert wird. Mindestens die der lonenstrahlung ausgesetzte Oberfläche der Maske ist elektrisch und thermisch leitfähig und mechanisch widerstandsfähig. Die Beschichtung des Siliciumgerüsts (1, 2) der Maske ist so ausgebildet, daß sie keine temperaturbedingte und/oder durch Eigenspannungen der Beschichtung bedingte Deformation der Maske verursacht. Bevorzugt dienen als absorbierende Materialien Gold, Silber, Platin, Wolfram und Tantal und als mechanisch widerstandsfähige Materialien Kohlenstoff, Molybdän, Titan, Wolfram und Tantal. Beim Einsatz wird die Maske mit dem Gitter (2) auf das zu bestrahlende Substrat aufgesetzt und dann mit einem lonenstrahl ganzflächig beleuchtet oder Zeile für Zeile überstrichen, bis jeder Punkt der Maske sich im Strahlengang befunden hat.
摘要:
A method for making low barrier Schottky devices by the electron beam evaporation of a reactive metal such as tantalum, titanium, hafnium, tungsten, molybdenum, and niobium which is selectively deposited at a semiconductor surface such as n-type silicon using a photoresist mask. The method includes a series of steps during the deposition of the barrier metal for degassing the semiconductor substrate (9), photoresist mask (25), reactive metal charge (17) and deposition chamber (2). The method may include steps for preliminarily degassing the substrate, mask and surrounding chamber (3) by infrared heating under vacuum, followed by steps for preliminarily degassing the charge and surrounding chamber (4), while the substrate and mask are shielded, by electron beam heating the charge while under vacuum. Thereafter, and prior to deposition, the substrate and mask can be finally degassed by irradiation with X-rays (31) produced by electron beam heating the charge to a temperature below evaporation for a predetermined time under vacuum. Upon further heating of the charge, the barrier metal is evaporated and deposited at the semiconductor substrate surface.
摘要:
With the method, in which the photoresist is exposed to radiation more than once, a hole pattern corresponding to the pattern of openings (15, 16) of an exposure mask (14) as well as a hole pattern corresponding to the negative of the pattern of openings (28, 29, 30) of another exposure mask (25) are sequentially produced in a single photoresist layer (12). The method is used e.g. in forming holes (23, 24) defined by the positive image into an oxide layer (11) on a substrate (10), and in producing a metallization pattern (36a, 36b) defined by the negative image for interconnecting areas of the substrate (10).
摘要:
The Schottky barrier diode having a self-aligned guard ring comprises a dielectric layer (3) on a silicon substrate said layer (3) having a substantially vertically walled hole therein, a doped silicon lining (5) being of uniform width covering the silicon along the walls of said hole and contact metal (7) on said substrate exposed within the inner perimeter of that lining (5). To produce such a diode a hole ist etched anisotropically into a dielectric layer (3) on a silicon substrate. Then a doped silicon layer (4) is deposited which is reactively ion etched, to expose said substrate through said hole. By heating the dopant in the remainder of said silicon layer (4) is diffused into the substrate. Onto the exposes substrate metal (7) is applied.