JP2005302755A - Semiconductor integrated circuit and management method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit management method which can indicate the management information by cutting a fuse, and can increase an amount of information on management indicated by cutting the fuse. <P>SOLUTION: In this management method for semiconductor integrated circuits, how many fuses 2 and 3 formed on a semiconductor integrated circuit are to be cut and where on the fuses they are cut are determined based on the management information on the semiconductor integrated circuit. Then, according to the determined cutting positions on the fuses 2 and 3 and the number of fuses to be cut, the fuses are cut by laser trimming. The management method thus obtained for semiconductor integrated circuits is suitable for identifying individuals. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor integrated circuit management method and a semiconductor integrated circuit, and more particularly to a semiconductor integrated circuit management method and a semiconductor integrated circuit provided with a fuse.

  Conventionally, an output buffer circuit capable of pull-up / pull-down setting and a resistance ladder circuit for adjusting an output voltage have been proposed. In the former circuit, pull-up or pull-down can be set depending on whether the fuse on the pull-up side is cut or the fuse on the pull-down side is cut. In the latter circuit, the combined resistance value can be changed by combining fuse cutting, and the output voltage can be adjusted. In this way, circuit characteristics have been adjusted by cutting a fuse.

  Fuse cutting in such a circuit is generally called trimming, and trimming using a laser is used as a general technique. In a general trimming technique, first, a characteristic test related to an item whose circuit characteristics are to be adjusted by cutting a fuse in a so-called previous process is performed. Based on the result of the characteristic test, the coordinates of the fuse to be cut are calculated and used as cutting coordinate information for the fuse cutting device.

  At this time, the combination of fuses to be cut is arbitrary for each LSI (Large Scale Integration) individual, but the cutting position for each fuse is the same for all LSI individual if at least the same type of LSI. Become. After the fuse cutting coordinates are obtained, the fuse cutting is performed by the fuse cutting device based on the cutting coordinate information.

  FIG. 4 shows the state of the fuse after trimming. In the figure, two fuses 2 and 3 are connected in series, one fuse 2 is connected to a pull-up power source 1, and the other fuse 3 is connected to a pull-down power source 4. A plurality of fuses having such a circuit configuration are provided. In this example, the fuses 2a, 3b, 2c, 3d, 3e, and 2f are cut at the cutting position 5 from the left side of the drawing in order to adjust the circuit characteristics. If the state after the fuse is blown is expressed as a numerical value (assuming it is a binary number), the pull-up fuse is cut and the pull-down portion is “0”, and the pull-down fuse is cut and the pull-up state is pulled up In this example, “010”, that is, “16h” is represented from the left side in the figure.

As a method for performing individual management of an LSI by cutting a fuse, there is a method (Patent Document 1, Patent Document 2) in which a fuse is provided exclusively for an individual management number. Further, in Patent Document 3, the protection element cut into the terminal pad of the circuit that has become unnecessary is separated by a combination corresponding to the lot number or wafer number, thereby enabling identification in units of wafers.
JP 2000-68458 A Japanese Patent Laid-Open No. 4-111438 Japanese Patent Laid-Open No. 3-203344

  Conventionally, one fuse is cut at a predetermined position for each fuse that is determined to be cut from a so-called pre-process characteristic test result. In general, it is highly likely that the combination of fuses to be cut is the same among LSIs manufactured at one time. Simply recording the pair of the fuse combination to be cut and the characteristic test result in the previous process. LSI individual management is not possible. Therefore, the one-to-one correspondence of LSI individual is lost when proceeding from so-called pre-process to post-process. Therefore, it is impossible to track the characteristic change between before trimming and after the post-process.

  In the methods according to Patent Document 1 and Patent Document 2, since the fuse cutting positions are basically the same, it is necessary to provide a dedicated trimming area for individual LSI management. Further, in the methods according to Patent Document 1 and Patent Document 2, since one place is cut in units of fuses, the amount of information held by cutting is small.

  In the method according to Patent Document 3, identification can be performed only at least in units of wafers, and individual identification in units of LSI is impossible. In Patent Document 3, since identification is performed by a combination of cutting of the protection elements cut into the terminal pads of the FAIL sample in the wafer, it is impossible in principle to identify individual products.

  An object of the present invention is to provide a semiconductor integrated circuit management method capable of solving such problems and expressing management information by cutting a fuse. In particular, an object of the present invention is to increase the amount of management information that can be expressed by blowing a fuse. A further object of the present invention is to provide a semiconductor integrated circuit management method suitable for individual identification.

  In order to achieve the above object, a method for managing a semiconductor integrated circuit according to the present invention includes a step of determining a cutting position in a fuse of a fuse formed on the semiconductor integrated circuit based on management information of the semiconductor integrated circuit. And cutting the determined cutting position in the fuse by laser trimming.

  Another method of managing a semiconductor integrated circuit according to the present invention includes a step of determining the number of cuts in a fuse of a fuse formed on the semiconductor integrated circuit based on the management information of the semiconductor integrated circuit, Cutting by laser trimming for the number of cuts in the fuse.

  According to another semiconductor integrated circuit management method of the present invention, the step of determining the cutting position and the number of cuts in the fuse of the fuse formed on the semiconductor integrated circuit based on the management information of the semiconductor integrated circuit; Cutting the fuse by laser trimming according to the determined cutting position and number of cuts in the fuse.

  Here, the fuse is preferably a fuse for circuit adjustment.

  Preferably, the management information is information for individual identification of the semiconductor integrated circuit.

  A test apparatus for a semiconductor integrated circuit according to the present invention includes means for associating a semiconductor integrated circuit with management information, a cutting position in a fuse of a fuse on the semiconductor integrated circuit associated with the management information based on the management information, and Means for determining the number of cuts, and means for calculating cutting coordinate information of the fuses based on the determined cutting position and / or number of cuts in the fuse.

  According to another aspect of the present invention, there is provided a testing apparatus for a semiconductor integrated circuit, a means for associating a semiconductor integrated circuit with a management number, a means for testing characteristics of the semiconductor integrated circuit, and the semiconductor integrated circuit based on the management number and a test result. Means for determining a cutting position and / or number of cuts in the fuse of the upper fuse, and means for calculating cutting coordinate information of the fuse based on the determined cutting position and / or number of cuts in the fuse of the fuse I have.

  The method for manufacturing a semiconductor integrated circuit according to the present invention includes a step of forming a fuse on the semiconductor integrated circuit, and a step of determining a cutting position of the fuse in the fuse based on management information of the semiconductor integrated circuit. Cutting a cut position on the fuse by laser trimming.

  Another method of manufacturing a semiconductor integrated circuit according to the present invention includes a step of forming a fuse on the semiconductor integrated circuit, a step of determining the number of cuts in the fuse of the fuse based on management information of the semiconductor integrated circuit, Cutting by laser trimming based on the determined number of cuts.

  According to another method of manufacturing a semiconductor integrated circuit according to the present invention, a step of forming a fuse on the semiconductor integrated circuit, and a cutting position and the number of cuts in the fuse of the fuse are determined based on management information of the semiconductor integrated circuit. And a step of cutting the determined position and number of cuts in the fuse by laser trimming.

  The semiconductor integrated circuit according to the present invention is one in which the fuse is cut by laser trimming according to the cutting position in the fuse of the fuse on the semiconductor integrated circuit determined based on the management information of the semiconductor integrated circuit.

  Another semiconductor integrated circuit according to the present invention is one in which the fuse is cut by laser trimming according to the number of cuts in the fuse on the semiconductor integrated circuit determined based on the management information of the semiconductor integrated circuit. .

  Another semiconductor integrated circuit according to the present invention is one in which the fuse is cut by laser trimming according to the cutting position and the number of cuts in the fuse of the fuse on the semiconductor integrated circuit determined based on the management information of the semiconductor integrated circuit It is.

  Here, the fuse in the semiconductor integrated circuit is preferably a fuse for circuit adjustment.

  ADVANTAGE OF THE INVENTION According to this invention, the management method of the semiconductor integrated circuit which can represent management information by cutting | disconnecting a fuse can be provided. In particular, the present invention can increase the amount of management information that can be represented by blown fuses. Furthermore, the present invention can provide a semiconductor integrated circuit management method suitable for individual identification.

  In the management method of the semiconductor integrated circuit according to the embodiment of the present invention, the management information of the semiconductor integrated circuit is used based on the cutting position and / or the number of cuts in each fuse. Here, the management information includes identification information of the LSI individual. That is, each LSI can be identified by the management information. Preferably, the management information is a management number. The management number can be composed of a wafer number, LSI coordinates on the wafer, the number of tests, or a combination thereof.

  For example, a polysilicon resistor is used as the fuse. The fuse is cut by laser trimming. Although there is a method of blowing the fuse by overcurrent, a method using a laser is optimal for controlling the cutting position.

  The fuse is a circuit adjustment fuse, and is used, for example, in a resistor ladder circuit for output voltage adjustment. In this circuit, the combined resistance value can be changed by combining fuse cutting, and the output voltage can be adjusted. Such a fuse is provided, for example, inside a silicon pellet. It is fixed at a constant voltage regardless of the input of the LSI. For example, when it is necessary to accurately determine the output voltage of the regulator circuit, in general, this may not be realized due to manufacturing variations. In such a case, a resistor ladder circuit or the like for adjusting the output voltage is built in the circuit, and the combined resistance value is changed by a combination of fuse cutting so that the output voltage can be adjusted individually for each LSI. . By doing this, fuse trimming is used because the adjustment value is uniquely determined regardless of the input state to the LSI.

  The fuse is also used, for example, as a pull-up / pull-down input of a buffer circuit that is to be fixed to a specific output state inside the LSI. In this circuit, pull-down or pull-up can be set depending on whether the fuse on the pull-up side is cut or the fuse on the pull-down side is cut. In addition to the regulator circuit and the buffer circuit, there are a number of circuit types and purposes that require fuse trimming, and the present invention is not limited to this example.

  Embodiments of each invention will be described below.

Embodiment 1 of the Invention
FIG. 1 shows the state of the fuse after trimming. In the figure, two fuses 2 and 3 are connected in series, one fuse 2 is connected to a pull-up power source 1, and the other fuse 3 is connected to a pull-down power source 4. A trimming bit output node is provided at a node connecting the fuse 2 and the fuse 3. In this example, in order to adjust the circuit characteristics, the fuses 2a, 3b, 2c, 3d, 3e, and 2f are cut at the cutting position 5 from the left side in the drawing. As with the prior art, the state after the fuse is blown is expressed as a numerical value (assuming it is a binary number), the pull-up side fuse is cut and the part in the pull-down state is “0”, and the pull-down side fuse is cut Assuming that the portion in the pull-up state is “1”, in this example, “010110”, that is, “16h” is represented from the left side of the figure.

  Furthermore, in the first embodiment of the present invention, the management information (management number) is represented by the fuse cutting position. In FIG. 1, a line indicated by A-A 'is a management number bit boundary line. Information is represented depending on which side (upper or lower side in the figure) of this management number bit boundary line. In this example, the upper side of the management number bit boundary line is “1” and the lower side is “0”. Since “up / down / up / down / up / down” are arranged from the left side of the figure, when “1” and “0” are replaced, “101101” is obtained. When this “101101” is expressed in hexadecimal, it is 2Dh.

  Here, since the number of LSIs formed on one wafer is about 200 to 3000, the number of bits for identifying an individual is sufficient if the identification is performed separately for each wafer. In this case, if the number of wafers per lot is about 20 to 30, 17 bits are sufficient even when management is performed for each wafer.

  Next, the fuse cutting flow in the previous process will be described with reference to the flowchart shown in FIG. The following steps S101 to S107 are executed in an LSI tester which is a semiconductor integrated circuit test apparatus.

  First, the management number is initialized when starting the characteristic test (S101). Next, a characteristic test is executed (S102). Based on the result of the characteristic test, the coordinates of the fuse to be cut are calculated (S103).

  Further, a coordinate offset in each fuse is calculated based on a management number determined in advance for each LSI, and added to the fuse coordinates calculated in step S103 (S104). The fuse cutting coordinate information obtained by the addition is recorded in a predetermined storage medium (S105).

  Next, the management number is updated (S106). For example, 1 is added to the immediately preceding management number to generate an updated management number. After the management number is updated, it is determined whether the LSI corresponding to the management number before the update is the last LSI (S107). If it is determined that it is not the last LSI, the LSI coordinates on the wafer are updated and step S102 is executed. As a result of the determination, if it is determined that it is the last LSI, the process proceeds to step S108. In step S108, calculation of the fuse cutting coordinates has been completed for all the LSIs, so the LSIs are transported to the fuse cutting device. In the fuse cutting device, the fuse is cut based on the calculated fuse cutting coordinates.

  Next, confirmation of the cutting position of the fuse that has been subjected to the cutting process will be described. After the dicing and package assembling process, each LSI individual is opened. This process exposes the surface of the LSI. Then, the management number is read by checking the cutting coordinates of the fuse on the exposed LSI surface. Thereby, the correspondence between the characteristic test result in the post-process and the fuse cutting coordinate information recorded in the pre-process can be obtained.

  As described above, in the first embodiment of the present invention, not only the information for adjusting the circuit characteristics but also the management information can be expressed by the cutting position of the fuse. It is possible to increase the amount of information without increasing. In particular, in this example, the management number that enables individual identification of the LSI is represented by the cutting position of the fuse, so that each LSI can be identified by observing the fuse.

  In addition, as individual LSI management becomes possible, analysis for optimizing circuit adjustment by fuse cutting becomes smooth. Furthermore, it can also be used for general trace management of LSI individuals.

Embodiment 2 of the Invention
In the second embodiment of the present invention, information can be further expressed by both the cutting position and the number of cuts of the fuse. Here, a management number in a quaternary number is assigned to each LSI according to the cutting position and the cutting number of the fuse.

  FIG. 3 shows the state of the fuse after trimming. Since the connection form of each fuse is the same as that of the first embodiment, the description thereof is omitted. In this example, in order to adjust the circuit characteristics, the fuses 2a, 3b, 2c, 3d, 3e, and 2f are cut at the cutting position 5 from the left side in the drawing. As in the prior art, the state after the fuse is blown is expressed as a numerical value (assuming a binary number), the pull-up fuse is cut and the part in the pull-down state is “0”, and the pull-down fuse is cut When the portion in the pull-up state is “1”, in this example, “010110”, that is, “16h” is represented from the left side of the figure.

  Furthermore, in the second embodiment of the present invention, the management information (management number) is represented by the cut position and the number of cuts of the fuse. In FIG. 3, a line indicated by A-A 'is a management number bit boundary line. Information is represented depending on which side (upper or lower side in the figure) of this management number bit boundary line. Further, the information is represented by one or two cuts. In this example, when the lower side of the management number bit boundary line is cut, it represents “0” or “1”. In this case, when the number of cuts is one, “0” is indicated, and when the number of cuts is two, “1” is indicated. When the upper side of the management number bit boundary line is cut, it represents “2” or “3”. In this case, when the number of cuts is one, “2” is indicated, and when the number of cuts is two, “3” is indicated.

  Then, the management number is “312103”. When “312103” is expressed in decimal, it is “3475”.

  As described above, in the second embodiment of the present invention, not only the information for adjusting the circuit characteristics but also the management information can be expressed by the cut position and the number of cuts of the fuse. It can be increased. In particular, in this example, the management number that enables individual identification of the LSI is represented by the cutting position of the fuse, so that each LSI can be identified by observing the fuse.

Other embodiments.
The management information can be expressed only by the number of cuts. For example, “0” may be represented when the number of cuts is 1, “1” when the number of cuts is 2, and “2” when the number of cuts is 3.

  In the embodiment of the above-described invention, the cutting position is provided with one boundary line, and information is represented by either side of the boundary line. However, the present invention is not limited to this, and by providing two or more boundary lines. It may be divided into three or more regions, and information may be represented according to which region has the cutting position.

  In the above example, the management information is identification information of the LSI individual, but is not limited thereto. For example, the management information includes lot identification information, wafer identification information, format code, wiring start year, wiring lot month code, wiring lot number suffix, chip address, trimming information, and the like.

  In the above example, the management information is represented by the position and / or the number of cuts of the fuse used for adjusting the circuit characteristics. However, the management information is independent of the fuse used for adjusting the circuit characteristics. The management information may be represented by the position and / or the number of cuts of the dedicated fuse provided. Note that cutting the fuse does not mean only complete cutting, but also includes a case where a hole is provided in the fuse by, for example, a laser.

It is a schematic diagram which shows the fuse part of LSI to which this invention is applied. It is a flowchart which shows the cutting process of the fuse concerning this invention. It is a schematic diagram which shows the fuse part of LSI to which this invention is applied. It is a schematic diagram which shows the fuse part of the conventional LSI.

Explanation of symbols

1 Pull-up power supply 2 Fuse 3 Fuse 4 Pull-down power supply

Claims (14)

Determining a cutting position in the fuse of the fuse formed on the semiconductor integrated circuit based on management information of the semiconductor integrated circuit;
And a step of cutting a determined cutting position of the fuse in the fuse by laser trimming. Determining the number of cuts in the fuse of the fuse formed on the semiconductor integrated circuit based on the management information of the semiconductor integrated circuit;
A method of managing a semiconductor integrated circuit, comprising: cutting by laser trimming for the number of cuts of the determined fuse in the fuse. Determining the cutting position and the number of cuts in the fuse of the fuse formed on the semiconductor integrated circuit based on the management information of the semiconductor integrated circuit;
And a step of cutting the fuse by laser trimming according to the determined cutting position and number of cuts in the fuse.   4. The semiconductor integrated circuit management method according to claim 1, wherein the fuse is a fuse for circuit adjustment.   5. The semiconductor integrated circuit management method according to claim 1, wherein the management information is information for individual identification of the semiconductor integrated circuit. Means for associating the semiconductor integrated circuit with the management information;
Means for determining a cutting position and / or the number of cuts in the fuse of the fuse on the semiconductor integrated circuit associated with the management information based on the management information;
And a means for calculating cutting coordinate information of the fuse based on the determined cutting position and / or number of cuts in the fuse. Means for associating a semiconductor integrated circuit with a management number;
Means for testing the characteristics of the semiconductor integrated circuit;
Means for determining a cutting position and / or the number of cuts in the fuse of the fuse on the semiconductor integrated circuit based on the control number and the test result;
And a means for calculating cutting coordinate information of the fuse based on the determined cutting position and / or number of cuts in the fuse. Forming a fuse on the semiconductor integrated circuit;
Determining a cutting position of the fuse in the fuse based on management information of the semiconductor integrated circuit;
And a step of cutting the determined cutting position of the fuse in the fuse by laser trimming. Forming a fuse on the semiconductor integrated circuit;
Determining the number of cuts in the fuse of the fuse based on management information of the semiconductor integrated circuit;
And a step of cutting by laser trimming based on the determined number of cuts. Forming a fuse on the semiconductor integrated circuit;
Determining the cutting position and the number of cuts in the fuse based on the management information of the semiconductor integrated circuit;
A method of manufacturing a semiconductor integrated circuit, comprising: cutting a determined position and number of cuts in the fuse by laser trimming.   A semiconductor integrated circuit in which the fuse is cut by laser trimming according to the cut position in the fuse of the fuse on the semiconductor integrated circuit determined based on the management information of the semiconductor integrated circuit.   A semiconductor integrated circuit in which the fuse is cut by laser trimming according to the number of cuts in the fuse of the fuse on the semiconductor integrated circuit determined based on the management information of the semiconductor integrated circuit.   A semiconductor integrated circuit in which a fuse is cut by laser trimming in accordance with a cutting position and the number of cuts in the fuse of the fuse on the semiconductor integrated circuit determined based on management information of the semiconductor integrated circuit. The semiconductor integrated circuit according to claim 11, wherein the fuse is a fuse for circuit adjustment.

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