Abstract:
A method is disclosed for forming an ultrathin oxide layer of uniform thickness. The method is particularly advantageous for producing uniformly thin interfacial oxides beneath materials of high dielectric permitivity, or uniformly thin passivation oxides. Hydrofluoric (HF) etching of a silicon surface, for example, is followed by termination of the silicon surface with ligands larger than H or F, particularly hydroxyl, alkoxy or carboxylic tails. The substrate is oxidized with the surface termination in place. The surface termination and relatively low temperatures moderate the rate of oxidation, such that a controllable thickness of oxide is formed. In some embodiments, the ligand termination is replaced with OH prior to further deposition. The deposition preferably includes alternating, self-limiting chemistries in an atomic layer deposition process, though any other suitable deposition process can be used. Two or more of the HF etching, surface termination, oxidation, hydroxyl replacement of the surface termination and deposition on the oxide can be conducted in situ.
Abstract:
A single-wafer, chemical vapor deposition reactor is provided with hydrogen and silicon source gas suitable for epitaxial silicon deposition, as well as a safe mixture of oxygen in a non-reactive gas. Methods are provided for forming oxide and silicon layers within the sane chamber. In particular, a sacrificial oxidation is performed, followed by a hydrogen bake to sublime the oxide and leave a clean substrate. Epitaxial deposition can follow in situ. A protective oxide can also be formed over the epitaxial layer within the same chamber, preventing contamination of the critical epitaxial layer. Alternatively, the oxide layer can serve as the gate dielectric, and a polysilicon gate layer can be formed in situ over the oxide.
Abstract:
A method of removing deposits from selected areas of a substrate-processing chamber comprising applying RF energy to a coil located around selected areas of the chamber is provided. Also provided is a substrate-processing chamber with improved cleaning properties having a coil capable of being coupled with an RF field disposed at selected areas of the chamber.
Abstract:
A substrate to be processed in a high temperature processing chamber is preheated to avoid the problems associated with thermal shock when the substrate is dropped onto a heated susceptor. Preheating is effected by holding the substrate over a susceptor maintained at or near the processing temperature until the temperature of the substrate approaches the processing temperature. Thus, wafer warping and breakage are greatly reduced, and wafer throughput is improved because of time saved in maintaining the susceptor at constant temperature without cool down and reheat periods.
Abstract:
The construction of a film on a wafer, which is placed in a processing chamber, may be carried out through the following steps. A layer of material is deposited on the wafer. Next, the layer of material is annealed. Once the annealing is completed, the material may be oxidized. Alternatively, the material may be exposed to a silicon gas once the annealing is completed. The deposition, annealing, and either oxidation or silicon gas exposure may all be carried out in the same chamber, without need for removing the wafer from the chamber until all three steps are completed. A semiconductor wafer processing chamber for carrying out such an in-situ construction may include a processing chamber, a showerhead, a wafer support and a rf signal means. The showerhead supplies gases into the processing chamber, while the wafer support supports a wafer in the processing chamber. The rf signal means is coupled to the showerhead and the wafer support for providing a first rf signal to the showerhead and a second rf signal to the wafer support.
Abstract:
Described herein is a process chamber with a substantially all-quartz interior surface. The preferred embodiments have upper and lower walls being curved in both the x-z and y-z planes. In one embodiment, the chamber has thin upper and lower dome walls made from a generally transparent material such as quartz, each with a convex exterior surface and a concave interior surface. These walls are joined at their side edges to a cylindrical side wall, preferably formed from a generally translucent material such as bubble quartz. The upper and lower walls and the side wall substantially enclose an all-quartz interior surface, except for apertures used for gas inlet and outlet, wafer intrusion and extraction and wafer retention. An internal reinforcement extends along the entire interior perimeter of the chamber to provide additional strength and support to the chamber. An external reinforcement surrounds the cylindrical side wall to confine outward expansion of the chamber. In another embodiment, the chamber has upper and lower dome walls that are curved along both their longitudinal and lateral axes, the walls being substantially rectangular when viewed from above.
Abstract:
The invention is a carrier comprising three support elements connected by an underlying frame. The periphery of a wafer rests upon the support elements. The invention also comprises a wafer handler with a plurality of arms. Spacers space the carrier above a base plate associated with a station in a wafer handling area. An arm slides beneath the frame and between the spacers, but the handler does not contact the wafer. A method of using the handler and carrier is provided where the handler lifts and rotates the carrier with the wafer through various stations in a wafer handling area. A control device reduces the handler speed only at critical points of the processing cycle. The handler is capable of moving a plurality of carriers and wafers simultaneously.
Abstract:
A system for facilitating wafer transfer comprises a susceptor unit consisting of an inner susceptor section which rests within an outer susceptor section. A vertically movable and rotatable support spider located beneath the susceptor unit can rotate into positions to engage either the inner or the outer susceptor sections. When the inner section is engaged, the support spider lifts the inner section vertically out of the outer section. When the outer section is engaged, the support spider raises and lowers the entire susceptor unit. A robotic arm end effector engaging only the lower surface of the outer edge of the wafer permits hot wafer pick-up and unloading by the inner susceptor section. Several end effectors are disclosed that minimize non-uniform thermal effect on the substrate.
Abstract:
Methods and apparatuses are provided for cooling semiconductor substrates prior to handling. In one embodiment, a substrate and support structure combination is lifted after high temperature processing to a cold wall of a thermal processing chamber, which acts as a heat sink. Conductive heat transfer across a small gap from the substrate to the heat sink speeds wafer cooling prior to handling the wafer (e.g., with a robot). In another embodiment, a separate plate is kept cool within a pocket during processing, and is moved close to the substrate and support after processing. In yet another embodiment, a cooling station between a processing chamber and a storage cassette includes two movable cold plates, which are movable to positions closely spaced on either side of the wafer.
Abstract:
The invention is a carrier comprising three support elements connected by an underlying frame. The periphery of a wafer rests upon the support elements. The invention also comprises a wafer handler with a plurality of arms. Spacers space the carrier above a base plate associated with a station in a wafer handling area. An arm slides beneath the frame and between the spacers, but the handler does not contact the wafer. A method of using the handler and carrier is provided where the handler lifts and rotates the carrier with the wafer through various stations in a wafer handling area. The handler is capable of moving a plurality of carriers and wafers simultaneously.