Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
  • H10F39/00—Integrated devices, or assemblies of multiple devices, comprising at least one element covered by group H10F30/00, e.g. radiation detectors comprising photodiode arrays
  • H10F39/10—Integrated devices

Definitions

• the present invention relates to a semiconductor image position detecting device used for measuring optical distance, position, movement, deformation, and the like, and in particular, a structure of a semiconductor image position detecting element suitable for high-precision measurement and an image using the same. It relates to a method for improving the accuracy of position detection.
• a resistive layer is provided on the photoelectric film layer, and the photocurrent generated by the optical image part projected on the photoelectric film Is transmitted through the resistive layer, reaches the output electrodes at both ends, detects the output currents that are output, and calculates these to calculate the center of gravity of the optical image of the photoelectric film layer.
• PSDs Position Sensitive Devices
• Examples of conventional PSDs are GP Petersson and L. J., Lindholnt, Position sensitive light detectors with high linearity, "IEEE J. Sol id-State Circuits, vol. SC-3, pp. 392-399, 1978, DJW Noorlag and S. Middelhoek, K Two-dimensional position sensitive pho tode tec tor with high linearity made with standard IC-technology, "IEEE J.
• FIG. 5 shows a conceptual diagram of a cross-sectional structure of a typical semiconductor position detecting element of this conventional type.
• a photocurrent is generated in the photoelectric layer P, passes through the resistance layer R, and is output from the output electrodes T A and T B.
• I and IE are output.
• the output currents I A and I are values obtained by dividing the photocurrent according to the resistance ratio of the resistive layer between the light incident position and the output electrodes T A and T b, and the difference between the output current values (I ⁇ I) value obtained by dividing the sum of the output current value (I + I) is a value proportional to the light incident position location X D from center. Therefore, the output currents I and I are input to the signal operation circuit shown in FIG.
• the image position detection accuracy of the conventional method largely depends on the accuracy of the analog signal processing system and the accuracy (resolution) of the analog-to-digital conversion. Improving the accuracy of analog arithmetic systems is not only extremely expensive, but in some cases it is almost impossible to achieve it. This is the reason for improving the accuracy of image position detection (higher resolution) in semiconductor image position detectors. It has become a major obstacle in the event.
• the present invention provides: Semiconductor image
• the detection area of the position detection element is divided into a plurality of sections, and any one section section or any section section can be selected according to the selection of the power electrode provided at the boundary of the section (hereinafter referred to as a section section).
• a plurality of continuous sections are configured to operate as one semiconductor image position detecting element, and an output electrode suitable for measurement is selectively used. In operation, first, an output electrode sandwiching a plurality of section sections is selected, and the section is operated as one semiconductor image position detecting element.
• the output electrodes at both ends of the section to which the light image belongs are selected (if the light image extends over a plurality of section sections, the output electrodes at both ends of the plurality of section sections), and the light image position within the selected section is selected. Is detected.
• the position of the light image is obtained by adding the electrode position in the selected section and the light image detection position in the selected section. Since the position of the output electrode at the boundary of the section can be physically extremely accurately manufactured, the image position detection accuracy is determined only by the image position detection accuracy within the selected section.
• the resolution of image position detection within the selected section is almost equal to the accuracy (resolution) determined by the analog analog and AZD converters. Performance is increased almost in proportion to the number of divisions. Even if the analog analog system and the AZD converter are exactly the same as before, the image position detection accuracy (resolution) is higher than that of the conventional system. It is significantly enhanced.
• FIG. 1 is a diagram conceptually showing a cross-sectional structure of a semiconductor image position detecting element based on the present invention
• Fig. 2 is a block diagram showing one configuration example of a signal processing circuit for operating the semiconductor image position detecting element according to the present invention in accordance with the image position detecting method based on the present invention.
• FIG. 3 is a cross-sectional view of another embodiment of the semiconductor image position detecting element according to the present invention.
• FIG. 4 is a perspective view showing one embodiment of a two-dimensional image position detecting element according to the present invention.
• FIG. 5 is a diagram conceptually showing a cross-sectional structure of a conventional typical semiconductor position detecting element (PDS), and
• Fig. 6 shows the signal processing for detecting the image position using the conventional PDS. Block diagram of the logic circuit.
• ⁇ Ka electrodes of minimum region width encompasses light incidence position (in Figure 1 and T 2) is selected, the output current from these, the light incident position X D within the selected interval Is obtained, the light incidence position Xs in the selected section is determined by the position accuracy obtained by dividing the selected section (T,, ⁇ ⁇ ) by the resolution of the AZD converter, and the position of the output electrode T t It can determine the light incidence positions across the and this adding together the X s.
• the positions of the output electrodes T A , Ti, ⁇ ⁇ ... T n , ⁇ ⁇ can be physically extremely accurately manufactured, and the stability is extremely high.
• the resolution for the entire detection section is (n + 1) X 2 n (1 6 xl, 0 2 4 ) next, without increasing the accuracy of the a / D converter, 2 n of the conventional method Compared with (1, 0 2 4), the resolution can be remarkably increased to (n + 1) (16) times.
• the resolution will be (n + 1) no 2 and half the above Even in some cases, the resolution can be significantly improved compared to the conventional method.
• the above describes the case where the image position detection accuracy is dominated by the accuracy of the A / D converter.However, even when the image position detection accuracy is dominated by the accuracy of the analog computing system, etc. The same is true.
• FIG. 2 is a block diagram of an output signal processing circuit provided with an output electrode selection switch.
• FIG. 2 shows a state in which the output electrodes T 1 and T 2 are selected, corresponding to FIG. Output current, it means that the output from the output electrode selected including the light incident position, the output electrode T Alpha of both ends, sweep rate output electrode selected corresponding to the T beta Tutsi S A and S b are always There is no problem even in the state of 0 N.
• an output electrode selection switch is shown as an external circuit in FIG. 2, the output electrode selection switch is integrated with an analog switch circuit in the semiconductor image position detecting element, and an external selection signal is used. It is desirable to configure so that an output signal from an output electrode in a desired section can be output.
• 3 shows that the image position can be detected over a wide range, and when light enters the specific range (interest area: between the output electrodes TMA and TMB ), the output electrodes TMA and TMB are selected and the image position is selected.
• 1 is an example of a cross-sectional structure of a semiconductor image position detecting element based on the present invention so that can be detected with high accuracy. Select the output electrodes T A and TE and check if the light incident position is within Is detected, and when it is within the interval of interest, the output electrodes T MA and T HB are selected, and the light incident position X M in this interval ⁇ is detected. The light incident position for the whole is obtained as the sum of the position X ⁇ of ⁇ and the light incident position X ⁇ in the target section.
• FIG. 4 shows an embodiment in which the present invention is applied to a two-dimensional image position detecting element, which is a semiconductor image position detecting element in which resistive layers R and Rz are divided into upper and lower surfaces, and the upper surface resistance is layer X direction, the resistance layer R 2 of the lower surface is used to image the position detection in the Y direction.
• a two-dimensional image position detecting element which is a semiconductor image position detecting element in which resistive layers R and Rz are divided into upper and lower surfaces, and the upper surface resistance is layer X direction, the resistance layer R 2 of the lower surface is used to image the position detection in the Y direction.
• the output electrode T, ⁇ ⁇ 1, ⁇ ⁇ 2, ⁇ ⁇ , and T Alpha selection of T yi, T Y2, T BY I do.
• the output electrodes cross in the X and Y directions. It is necessary to have a structure that is insulated from each other.
• the accuracy of the power supply system, the signal processing circuit, the AZD converter, etc. is the same as the conventional one, and the image position detection resolution is almost proportional to the number of sections. This makes it possible to achieve high-precision image position detection over a wide range, which was almost impossible with conventional semiconductor image position detecting elements and image position detecting elements.

Landscapes

• Length Measuring Devices By Optical Means (AREA)
• Measurement Of Optical Distance (AREA)
• Testing Or Measuring Of Semiconductors Or The Like (AREA)
• Photo Coupler, Interrupter, Optical-To-Optical Conversion Devices (AREA)

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Citations (3)

• 1987
  • 1987-07-02 JP JP62165969A patent/JPS6410108A/ja active Granted
• 1988
  • 1988-07-01 WO PCT/JP1988/000662 patent/WO1993014376A1/ja not_active Ceased

Patent Citations (3)

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