Abstract:
A method for removing a photoresist layer from a semiconductor substrate following a conventional dry etching step. A first wet chemical treatment strips the photoresist. A second dry ash with oxygen plasma completes the photoresist removal. To assure complete removal of photoresist imbedded on or within the material underlying the photoresist film, the semiconductor substrate is preheat treated to a temperature in the range of 150 to 250 degrees Centigrade to release the photoresist prior to the second dry ash with oxygen plasma operation. In particular, this method eliminates photoresist extrusion defects from occurring during a bond pad alloy operation.
Abstract:
A method for controlling the mask bias of a photoresist mask is described whereby a polymer coating is formed over the patterned photoresist mask immediately prior to etching the mask's pattern into a subjacent layer. The polymer coating is formed by treatment of the photoresist mask with a plasma, struck in within a reactive ion etching tool, in a gas mixture containing chlorine and helium. The etch durability and the thickness of the polymer coating determines the dimensional bias of the mask with respect to the pattern formed in the subjacent layer. By varying the polymer formation parameters a controllable etch bias between -0.01 and +0.03 microns can be achieved. This capability is particularly useful for patterning in integrated circuits where critical dimensions approach the resolution limits of the photolithography. The method is applied to the patterning of a silicon nitride hardmask employed in the formation of field oxide isolation (LOCOS) where a zero bias condition is achieved. The polymer coating can be formed in the same tool that is used to etch the hardmask, making the process simple and cost effective.
Abstract:
A wafer transfer robot for a wafer processing system, such as a wet bench system, and a method for utilizing the robot. The wafer transfer robot can be constructed by a robot arm that is equipped with a plurality of wafer blades each adapted for picking-up and carrying one of a plurality of wafers. The plurality of wafer blades each has a predetermined thickness, a top surface, a bottom surface and a predetermined spacing from adjacent wafer blades. A plurality of sensors, such as optical sensors, capacitance sensors or magnetic sensors, with at least one mounted on the bottom side of one of the plurality of wafer blades for sensing the presence of metal on a wafer carried on an adjacent wafer blade immediately below the one of the plurality of wafer blades.
Abstract:
A new method for detecting blind holes in the contact layer of a multi-chip semiconductor test wafer makes use of the fact that if the hole is not a blind hole, a subsequent etch step extends the hole a predetermined distance into the layer immediately underlying the contact layer. After a predetermined number of holes have been etched through the contact layer and for a predetermined distance into the layer underlying the contact layer, the contact layer is stripped to expose the holes in the underlying layer. These holes are scanned optically by a commercial apparatus that ordinarily detects wafer defects that resemble the holes. The missing holes are detected by comparing the holes of different chips on the test wafer. The test is particularly useful with a high density plasma etch because these holes typically have a very small diameter in relation to the thickness of the contact layer.
Abstract:
There is first provided a substrate 10 and a target layer 12. There is then formed upon the target layer a patterned positive photoresist layer 14. There is then processed the target layer while employing the patterned positive photoresist layer as a mask layer, to thus form a processed target layer and a processed patterned positive photoresist layer. There is then photoexposed 18 the processed patterned positive photoresist layer to enhance its solubility. Finally, there is then stripped from the processed target layer the photoexposed processed patterned positive photoresist layer while employing a solvent.
Abstract:
A method for determining the number of contaminating particles in a process chamber is described. While the method is particularly suited for detecting particles in a metal etch chamber, the present invention novel method can be utilized in any other semiconductor process chambers as long as there is a particle contamination problem. The method is carried out by conducting at least two particle dislodging cycles each including a step of flowing at least one process gas used in the process into the chamber at a flow rate of at least 30 sccm, and then evacuating the at least one process gas from the chamber to a pressure of not higher than 1 mTorr. Typical process gas that can be utilized in a metal etch chamber includes Cl2, BCl3 and Ar. The process gas should be flown into the etch chamber until a chamber pressure of at least 6 mTorr is reached, and preferably until at least a chamber pressure of 8 mTorr is reached. After the particle dislodging cycles are conducted, the number of particles that have fallen onto a top surface of the substrate can be counted by a particle counter.
Abstract:
Within a method for fabricating a microelectronic fabrication there is first provided a substrate. There is then formed simultaneously within the substrate an alignment mark and an isolation trench formed employing a single etch method and to an identical depth within the substrate. There is then formed within the isolation trench an isolation region. Finally, there is then further processed the substrate while aligning the substrate while using the alignment mark in conjunction with a minimum of two alignment wavelengths. The method provides for enhanced efficiency when fabricating the microelectronic fabrication. The method contemplates a microelectronic fabrication fabricated employing the method.