Abstract: A focused ion beam is used to etch material from a specimen while directing a vapor of 1,2 di-iodo-ethane at the surface being etched. The etch rate is accelerated for surfaces of aluminum and gold relative to the etch rate without use of 1,2 di-iodo-ethane.

Abstract: A method and apparatus for transmitting and receiving acquired digital data over bandpass channels (i.e. channels having a limited range of frequencies) at high data transmission rates. Combined amplitude and phase modulation (quadrature amplitude modulation) is applied to the digital data and the sampled digital waveform converted to an analog waveform for passage over the bandpass channel. The sample rate is chosen as an integer multiple of the symbol rate and carrier frequency to significantly reduce processing overhead. Reception of the acquired data is similar to transmission and involves an analogous amplitude and phase demodulation. The quadrature amplitude modulation technique of the present invention is applied to an oil well-logging application to transmit the data acquired from the downhole logging instruments over the logging cable (bandpass channel) at high transmission rates.

Abstract: Methods are provided for exposing a selected feature of an IC device, such as a selected conductor, from the back side of the substrate without disturbing adjacent features of the device, such as active regions. One such method comprises: (a) determining a region of the IC device in which the selected feature is located; (b) acquiring from the back side of the substrate an IR optical microscope image of the region; (c) aligning the IR optical microscope image with a coordinate system of a milling system; and (d) using structures visible in the IR optical microscope image as a guide, operating the milling system to expose the selected feature from the back side of the IC device without disturbing adjacent features.

Abstract: A method and apparatus for predicting the peak voltage at the load end of a power transmission cable having a power supply end and a load end, where direct measurement at the load end is not practical. The method samples the current and voltage waveforms at the power supply end of the cable. The current waveform is used to estimate a current function which includes a full width at half maximum and adjustments for cable reactive current, distortions, and load. The product of the current function and a peak voltage sample from the power supply end is an estimate of the peak voltage at the load end. The method and apparatus have been applied to oil well logging where one or more logging tools are lowered at the end of a transmission cable into an oil well and it is desirable to predict peak voltage at the tools to ensure proper tool performance. An important improvement is a more accurate current function which compensates for capacitive current flow in the cable and includes a quadratic term.

Abstract: A system and method for evaluating a geological formation is described which compares actual wireline log measurements from a number of wireline logging tools to predicted tool response logs. The system and method uses a forward model of each tool response, given a formation description, to predict a set of wireline logs. Comparing the predicted logs with the actual measured logs yields a mismatch error. The system and method iteratively adjusts the formation description to minimize the mismatch error to obtain a "best" formation description. In one form, the formation description includes petrophysical properties (porosity, density, saturation) and geometry properties (dip, bedding, invasion). In a more complicated form, the formation description also includes a model of petrophysical mixing laws and formation material content. In the special case of a horizontally layered formation and linear tool response models, there exists a computationally efficient version of the system and method.

Abstract: A method, useful in computer-aided design, of identifying possible solutions to an over-constrained system having a collection of entities and constraints. The method represents the entities in terms of degrees of freedom and incrementally assembles the system by adding entities, satisfying constraints and reducing the degrees of freedom of the entities. For an over-constrained system, the method constructs a dependency graph of the system and identifies the set of constraints which over-constrains the system. The over-constraining set includes the constraint which initiated the over-constraint and those constraints back traced in the dependency graph from the initiating constraint. Removal of one or more constraints from the over-constraining set results in a solvable fully or under-constrained system. Intelligent selection of the removed constraint may increase computational efficiency or system stability.

Abstract: A method for 3 dimensional, one pass migration of post stack seismic data is implemented on a massively parallel computer. The quality of the migration and speed of execution makes possible iterative 3D post stack depth migrations. The depth migration method computes in the frequency domain and downward continues one or more frequency planes through all depth levels of interest. For a single frequency, at each depth level, the method extrapolates a shifted position for each x,y position by applying a filter for 2D convolution. A processing component is assigned to each subgrid of x,y spatial positions and the processing components operate concurrently in parallel to determine filter coefficients independently for each x,y spatial position and to extrapolate the x,y shifted positions. The filter coefficients are derived independently at each x,y position by storing a limited table of filter coefficients in local memory of each processing component.