Abstract: An apparatus and method are provided for efficiently and effectively coating a substantially flat surface, i.e., a substrate, with a high-viscosity chemical such as photoresist. The chemical is dispensed through a piezo electrically controlled droplet jet cartridge on to the surface. The thickness of the chemical coating is controlled by controlling the rate at which chemical is dispensed through the droplet jet cartridge. A number of droplet jet cartridges are aligned such that gaps in chemical dispensed by one droplet jet cartridge are filled by chemical dispensed by other droplet jet cartridges. An array of droplet jet cartridges which spans the width of the surface moves across the surface to coat the surface with chemical in a single pass. To coat a circular surface, the surface is spun while a droplet jet cartridge is moved from the center of the surface to the outer edge of the surface. Chemical is dispensed on to the surface in a helical pattern.

Abstract: A substrate photolithography system includes a substrate handling robot that pivots about a fixed point and transfers substrates between photoresist coater, a developer, and a heating/cooling unit, all of which are clustered about the robot. The end effector of the robot is capable of both vertical and lateral movement so that individual modules of the heating/cooling unit may be stacked. For heating/cooling, the substrate is placed in the heating/cooling unit in close proximity to a hotplate/chillplate and a thermally conductive, non-reactive gas, such as helium, is introduced into the airspace between the substrate and the hotplate/chillplate. The thermally conductive, non-reactive gas, is preheated/precooled before introduction into the airspace between the substrate and the hotplate/chillplate when the gas passes through a bore in the hotplate/chillplate. Additionally, the substrate is automatically aligned in a milled recession in the hotplate surface for future handling.

Abstract: An apparatus and method are provided for controlling the rate of drying of a high-viscosity chemical applied to a substantially flat surface of a spinning article. The rate of drying of the chemical is controlled by controlling the saturation level of a solvent in the local atmosphere in which the article is spinning, i.e., in the air space adjacent to the surface of the article. By spinning the article in a solvent-laden vapor, the evaporation of solvent from the chemical is slowed and therefore the rate at which the chemical dries and thickens is also slowed. Spreading of the chemical may also be facilitated and premature drying of the chemical may be avoided by applying to the surface of the article a thin layer of the solvent prior to application of the chemical.

Abstract: In the resist development method disclosed herein, the spin development of a resist coating on the surface of a semiconductor wafer is monitored by measuring light scattered back from the wafer surface from an incandescent source. During development, the sensed light level oscillates due to optical fringing caused by the thinning of the resist layer in the exposed areas and the fringe generated oscillation essentially stops when the development breaks through in the exposed areas. By comparing sample data obtained from the sensed light level with template data representing a known or characteristic behavior, a control point corresonding to the last fringe may be determined. Development is then terminated a calculated time after the control point.