摘要:
A method for controlling wafer temperature in a thermal reactor. A wafer is positioned between two or more surfaces, one or more of which are heated. A control temperature is calculated based on the temperatures of the surfaces. The heat applied to the surface(s) is adjusted in response to the control temperature in order to maintain the wafer temperature within narrowly defined limits.
摘要:
A method for in-situ cleaning of a hot wall RTP system. Internal components are heated to high temperatures above 500° C. A halocarbon gas, inert gas and oxidizing gas are flowed through the reactor for a period which may exceed 20 minutes and then purged to remove contaminants.
摘要:
A semiconductor substrate processing system and method of using a stable heating source with a large thermal mass relative to conventional lamp heating systems. The system dimensions and processing parameters are selected to provide a substantial heat flux to the substrate while reducing the potential of heat loss to the surrounding environment, particularly from the edges of the heat source and substrate. Aspects of the present invention include a dual resistive heater system comprising a base or primary heater, surrounded by a peripheral or edge heater. The impedance of the edge heater may be substantially matched to that of the primary heater such that a single power supply may be used to supply power to both heaters. Both resistive heaters deliver heat to a heated block, and the heaters and heated block are substantially enclosed within an insulated cavity. The walls of the insulated cavity may include multiple layers of insulation, and these layers may be substantially concentrically arranged. The innermost layers may comprise silicon carbide coated graphite; the outer layers may comprise opaque quartz. An embodiment of the invention includes a vacuum spool having a large conduction pathway for exhausting gases from the region of the chamber containing the resistive heaters, and a small conduction pathway for removing gases from other regions of the chamber. Temperature measurement sensors include thermocouples and optical pyrometers, with the advantage that a thermocouple may be used to calibrate an optical pyrometer in situ. An insulating shutter may be used to insulate the port through which substrates are inserted into the insulated and heated cavity. Support posts and gas injectors may include ports for optical pyrometers.
摘要:
A plasma reactor and methods for processing semiconductor wafers are described. Gases are introduced into a reactor chamber. An induction coil surrounds the reactor chamber. RF power is applied to the induction coil and is inductively coupled into the reactor chamber causing a plasma to form. A split Faraday shield is interposed between the induction coil and the reactor chamber to substantially block the capacitive coupling of energy into the reactor chamber which may modulate the plasma potential. The configuration of the split Faraday shield may be selected to control the level of modulation of the plasma potential. For etch processes, a separate powered electrode may be used to accelerate ions toward a wafer surface. For isotropic etching processes, charged particles may be filtered from the gas flow, while a neutral activated species passes unimpeded to a wafer surface.
摘要:
A plasma reactor and methods for processing semiconductor wafers are described. Gases are introduced into a reactor chamber. An induction coil surrounds the reactor chamber. RF power is applied to the induction coil and is inductively coupled into the reactor chamber causing a plasma to form. A split Faraday shield is interposed between the induction coil and the reactor chamber to substantially block the capacitive coupling of energy into the reactor chamber which may modulate the plasma potential. The configuration of the split Faraday shield may be selected to control the level of modulation of the plasma potential. For etch processes, a separate powered electrode may be used to accelerate ions toward a wafer surface. For isotropic etching processes, charged particles may be filtered from the gas flow, while a neutral activated species passes unimpeded to a wafer surface.
摘要:
Apparatus and process for controlling etching of silicon-based or organic materials on large rectangular substrates for manufacture of flat panel displays or other devices. The disclosed etching process can remove silicon-based materials or organic polymers with a rate distribution such that all areas of the panel are finished at nearly the same time. It does so while minimizing electrical charging of the workpiece that could cause damage to the devices. The etching chamber employs a parallel plate RF discharge between two electrodes, one of which is the showerhead for gas introduction and the other supports the substrate to be processed. Reactant and other gases are provided to the discharge by a novel showerhead structure. The gases which provide reactants for etching silicon-based materials include halogenated compounds. Oxygen, water vapor or hydrogen with other gas additives may be used for etching organic polymers. The uniformity of etching across the substrate is controlled by adding other gas(es), including inert diluents, which can control the etching rate for either silicon-based materials or organic materials by accelerating and/or decreasing it. In addition, the distribution of the gases which are added can be varied to make the surface potential of the substrate more uniform. With a showerhead having a single reservoir that feeds all gases into the discharge, the gases may be added to the reservoir through multiple distribution structures within or adjacent to the reservoir. These structures are each supplied separately with the additive gases and, in turn, feed them to the different regions of the reservoir. The invention can thus provide different etching rates for different parts of the substrate, as may be required to finish film removal in all areas of the panel at nearly the same time. The invention also provides for chemical conversion of inorganic residues remaining after the oxidation of an organic polymer in the ashing process by addition of small amounts of halogenated gas(es) to the mixture flowing through the plasma sources. With the system and process of the invention, space efficiency, operating cost and capital cost for making large substrates can be reduced significantly.
摘要:
A more uniform plasma process is implemented for treating a treatment object using an inductively coupled plasma source which produces an asymmetric plasma density pattern at the treatment surface using a slotted electrostatic shield having uniformly spaced-apart slots. The slotted electrostatic shield is modified in a way which compensates for the asymmetric plasma density pattern to provide a modified plasma density pattern at the treatment surface. A more uniform radial plasma process is described in which an electrostatic shield arrangement is configured to replace a given electrostatic shield in a way which provides for producing a modified radial variation characteristic across the treatment surface. The inductively coupled plasma source defines an axis of symmetry and the electrostatic shield arrangement is configured to include a shape that extends through a range of radii relative to the axis of symmetry.
摘要:
Apparatus and method for an improved etch process. A power source alternates between high and low power cycles to produce and sustain a plasma discharge. Preferably, the high power cycles couple sufficient power into the plasma to produce a high density of ions (≳1011 cm−3) for etching. Preferably, the low power cycles allow electrons to cool off to reduce the average random (thermal) electron velocity in the plasma. Preferably, the low power cycle is limited in duration as necessary to prevent excessive plasma loss to the walls or due to recombination of negative and positive ions. It is an advantage of these and other aspects of the present invention that average electron thermal velocity is reduced, so fewer electrons overcome the plasma sheath and accumulate on substrate or mask layer surfaces. A separate power source alternates between high and low power cycles to accelerate ions toward the substrate being etched. In one embodiment, a strong bias is applied to the substrate in short bursts. Preferably, multiple burst occur during the average transit time for an ion to cross the plasma sheath and reach the substrate surface. Ions are pulsed toward the surface for etching. These ions are not deflected into sidewalls as readily as ions in conventional low energy etch processes due to reduced charge buildup and the relatively low duty cycle of power used to pulse ions toward the substrate surface.
摘要:
An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls. Further, peak power requirements are very small compared to lamp-heated RTPs because the cavity temperature is not cycled and the thermal mass of the cavity is relatively large. Increased speeds of insertion and/or removal may also be used with non-isothermal furnaces.
摘要:
Plasma assisted low temperature radical oxidation is described. The oxidation is selective to metals or metal oxides that may be present in addition to the silicon being oxidized. Selectivity is achieved by proper selection of process parameters, mainly the ratio of H2 to O2 gas. The process window may be enlarged by injecting H2O steam into the plasma, thereby enabling oxidation of silicon in the presence of TiN and W, at relatively low temperatures. Selective oxidation is improved by the use of an apparatus having remote plasma and flowing radicals onto the substrate, but blocking ions from reaching the substrate.