Method and apparatus for inspecting defects of semiconductor device
When an inspection apparatus of a semiconductor device repeatedly executes computation of prescribed area data, such as image processing for detecting defects, procedures for commanding, data load, computation, and data store need to be repeated the number of times of the computation. This may impose a limitation on the speeding up of the operation. In addition, when performing parallel computation by a high-capacity image processing system for handling minute images, a lot of processors are needed, resulting in an increase in cost. In order to solve the above-mentioned problems, in the invention, an inspection apparatus of a semiconductor device includes a data memory including an access section which is capable of reading and writing simultaneously, a plurality of numerical computation units, a connector for connecting the data memory and the numerical computation units, a controller for collectively controlling the contents of processing by the plurality of numerical computation units, another connector for connecting the numerical computation units and the controller, and a data transfer controller for controlling data transfer between the numerical computation units.
1. An apparatus for inspecting defects of a semiconductor wafer, comprising:
image obtaining means for sensing a surface of the semiconductor wafer and detecting image data of pixels in sequence;
image processing means for processing the image data obtained by the image obtaining means, extracting defects from the image data and classifying the defects; and
output means for outputting the classified defects;
wherein the image processing means has
a data memory part which has a two-dimensional memory array of M×N pixel size sequentially storing a plurality of N×1 pixel size data obtained by said image obtaining means, and each of said N×1 pixel size data being sequentially stored into the memory array,
an operation array which provides M operation units,
each of said N×1 pixel size data being processed in sequence by a corresponding one of said M operation units of the operation array for every N×1 pixel size data sequentially stored in said memory array,
an instruction memory which stores prescribed program code,
a master sequencer which transmits a control signal based on the program code stored in the instruction memory and collectively controls the operation units, and
a shift bus which only connects adjacent ones of said M operation units and which shifts the image data bidirectionally only between adjacent ones of said M operation units of the operation array.
2. The apparatus for inspecting defects of a semiconductor wafer according to claim 1 , wherein said image obtaining means is optical image obtaining means of a dark field type, or of a bright field type.
3. The apparatus for inspecting defects of a semiconductor wafer according to claim 1 , wherein said image obtaining means is SEM type image obtaining means adapted for irradiating and scanning the semiconductor device with a converged electron beam so as to detect a secondary electron therefrom.
4. The apparatus for inspecting defects of a semiconductor wafer according to claim 1 , wherein said M operation units are connected in rows in parallel, and said shift bus transmits the data between the M operation units connected in rows in parallel.
5. The apparatus for inspecting defects of a semiconductor wafer according to claim 1 , wherein said image processing means further includes a data storage section for storing therein a result of the computation by each of said M operation units connected in rows in parallel, and said shift bus connects said data storage section to a pipeline structure.
6. The apparatus for inspecting defects of a semiconductor wafer according to claim 1 , wherein said output means outputs a result processed by said image processing means to an external processor.
7. A method for inspecting defects of a semiconductor, wafer comprising the steps of:
obtaining an image of a semiconductor device for sensing a surface of the semiconductor water and detecting image data of pixels in sequence; and
processing the image data obtained to detect a defect on the semiconductor device, and extracting defects from the image data and classifying the defects,
wherein in the image processing step,
sequentially storing a plurality of N×1 pixel size data obtained by said image obtaining means in a data memory part which has a two-dimensional memory array of M×N pixel size,
processing said N×1 pixel size data with an operation array providing M operation units,
said N×1 pixel size data each being processed in sequence by corresponding ones of said M operation units of the operation array for every N×1 pixel size data sequentially stored in said memory array,
storing in an instruction memory prescribed program code,
transmitting by a master sequencer a control signal based on the program code stored in the instruction memory and collectively controls the operation units, and
shifting by a shift bus, which only connects adjacent ones of said M operation units, the image data bidirectionally only between adjacent ones of said M operation units of the operation array.