Abstract:
A system (10) for directly measuring the depth of a high aspect ratio etched feature on a wafer (80) that includes an etched surface (82) and a non-etched surface (84). The system (10) utilizes an infrared reflectometer (12) that in a preferred embodiment includes a swept laser (14), a fiber circulator (16), a photodetector (22) and a combination collimator (18) and an objective lens (20). From the objective lens (20) a focused incident light (23) is produced that is applied to the non-etched surface (84) of the wafer (80). From the wafer (80) is produced a reflected light (25) that is processed through the reflectometer (12) and applied to an ADC (24) where a corresponding digital data signal (29) is produced. The digital data signal (29) is applied to a computer (30) that, in combination with software (32), measures the depth of the etched feature that is then viewed on a display (34).
Abstract:
A measurement system for measuring aspects of a wafer combines an apparatus for performing a conductivity measurement, such as a four-point probe system, with apparatus for performing an optical measurement, such as a photoacoustic measurement system. Results are obtained and combined to provide comprehensive data sets describing the characteristics of the thin film substrate therein.
Abstract:
An apparatus protects a portion of a peripheral region (310) of a photoresist-coated surface of a substrate (308) from light exposure. The apparatus includes a blade (502, 512, 522, 532) that can move, or that can move and rotate, and a drive assembly (504, 514, 524, 534) operably coupled to the blade. In response to at least one first drive force generated by the drive assembly, the blade translates, rotates, or translates and rotates, such that the blade is disposed above a portion of the peripheral region. In response to at least one second drive force generated by the drive assembly, the blade translates, rotates, or rotates and translates, such that the blade is not disposed above a portion of the peripheral region. In a step-and-repeat lithographic system, the blade covers a portion of the peripheral region, and the adjacent portion of the substrate is exposed to light.
Abstract:
An apparatus (1100) for protecting at least a portion of a peripheral region of a photoresist-coated surface of a substrate from light exposure. The apparatus includes two or more movable blades (1102) and a drive assembly (1112, 1114) operably coupled to the movable blades. In response to at least one first drive force generated by the drive assembly, the movable blades translate such that the movable blades are disposed above at least a portion of the peripheral region. In response to at least one second drive force generated by the drive assembly, the movable blades translate such that the movable blades are not disposed above a portion of the peripheral region.
Abstract:
An automatically adjustable method for use in opto-acoustic metrology or other types of metrology operations is described. The method includes modifying the operation of a metrology system that uses a PSD style sensor arrangement. The method may be used to quickly adjust the operation of a metrology system to ensure that the data obtained therefrom are of the desired quality. Further, the method is useful in searching for and optimizing data that is or can be correlated to substrate or sample features or characteristics that of interest. Apparatus and computer readable media are also described.
Abstract:
An apparatus for improving the signal to noise ratio of measurements of the thickness of layers in a thin film stack uses a photoacoustic measurement system that includes a time differentiation system for inducing a delay in pump beam pulses. The time differentiation system uses, among other things, a birefringent element and other elements to control the polarization of pump beam pulses. Use of the apparatus involves applying a time varying voltage to an electro-optic modulator driver and setting a time differentiation step; or, in another embodiment, applying a time varying voltage to an electro-optic modulator to induce a fixed time delay delta-t between a vertically polarized pulse and a horizontally polarized pulse. The high frequency operation of the system provides for improved determinations of film thickness.