JP2000174211A - Semiconductor-trimming device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor-trimming device and method for reducing the number of pads required for trimming. SOLUTION: In a trimming method, an anti fuse 2 with a larger current value required for shifting state than a fuse 1 is connected in parallel with a series circuit consisting of the fuse 1 and a resistor 3 with a specific resistance, the state of the fuse 1 is shifted to a semiconductor trimming device 11 with a specific resistance as an initial state according to circuit characteristics, and a current for preventing the state of the anti fuse 2 from being shifted is applied for open-circuiting, or a sufficient current for shifting the anti fuse 2 to the short-circuited state is applied for shifting to short- circuited state and hence performing trimming and reducing the number of pads.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a semiconductor trimming apparatus used for circuit adjustment of a semiconductor integrated circuit and a trimming method therefor.

[0002]

2. Description of the Related Art Among the trimming elements used in a semiconductor integrated circuit, as means for electrically trimming, generally, means for shifting from an open state to a short-circuit state (hereinafter referred to as "anti-fuse"). And a Zener zap diode, and a polysilicon fuse or an aluminum fuse is used as a means for shifting from a short-circuit state to an open state (hereinafter referred to as “fuse”).

Next, an example of a conventional trimming means will be described with reference to FIGS.

First, a semiconductor trimming device 14 having a circuit configuration shown in FIG. 4 has a means for shifting from a short-circuit state to an open state. The fuse 1a and the resistor 3a are connected in parallel between the needle standing pads 4a and 4b, and the fuse 1b and the resistor 3b are connected in parallel between the pads 4b and 4c. These two parallel circuits are connected in series.

In this configuration, when the fuse 1a is shifted to the open state, a resistor 3a appears between the pads 4a and 4b,
When the fuse 1b is shifted to the open state, the pad 4
A resistor 3b appears between b and 4c, and trimming is performed. The state transition of the fuses 1a and 1b is performed by applying a corresponding current.

The second is a semiconductor trimming device 15 having a circuit configuration shown in FIG. 5, which is provided with means for shifting from an open state to a short-circuit state. Antifuse 2 between pad 4a and 4b for needle stand
a and the resistor 3a are connected in parallel, and the antifuse 2b and the resistor 3b are connected in parallel between the pads 4b and 4c. These two parallel circuits are connected in series.

In this configuration, when the anti-fuse 2a is shifted to the short-circuit state, the resistance between the pads 4a and 4b becomes approximately "zero", and when the anti-fuse 2b is shifted to the short-circuit state, the resistance between the pads 4b and 4c is reduced. The resistance becomes approximately “zero” and trimming is performed. The state transition of the anti-fuse 2a, 2b is performed by applying a corresponding current.

In the actual circuit adjustment, after the semiconductor manufacturing process is completed, a tester is used to set a needle on a needle holder pad, the circuit characteristics are measured, and if it is determined that adjustment is necessary, Circuit characteristics are adjusted by shifting the state of the trimming element.

However, conventional trimming requires pads for supplying current at both ends of each trimming element, and the number of pads is the number of adjustment bits plus one.

[0010]

As described above, in the conventional trimming method, the number of pads required for n-bit adjustment is n + 1, but the size of the pad is approximately 100 μm from the standpoint of needle placement accuracy. × 100 μm is required. Therefore, when the number of adjustment bits increases, the area occupied by the pads increases, which causes a problem that the chip area increases. In addition, since the number of pads is limited by the number of pins of the tester, it is difficult to increase the number of adjustment bits.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a semiconductor trimming device in which the number of pads required for trimming is reduced, and a trimming method therefor.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has been made in consideration of the following problems.
And a semiconductor trimming device having a trimming structure capable of moving to any of the open state and the open state. The predetermined resistance value is in a range of 1 kΩ or more and 100 kΩ or less, and the short-circuit state is a state in which the resistance value is one digit or more lower than the predetermined resistance value, and the open state is a predetermined state. This is a state where the resistance value is higher by one digit or more than the resistance value.

[0013] The semiconductor trimming device includes a series connection of a first trimming means for shifting from a short-circuit state to an open state and a semiconductor resistance element having a predetermined resistance value.
It is possible to adopt a configuration in which a second trimming unit that shifts from an open state to a short-circuit state and that requires a larger current for state transition than the first trimming unit is connected in parallel.

Here, the first trimming means is shifted from the short-circuit state to the open state, and a current for keeping the second trimming means in the open state is applied to open the first trimming means from the set resistance value in the initial state. Circuit trimming for shifting to a state and, if necessary, circuit trimming for shifting to a short-circuit state by applying a current for shifting the second trimming means from an open state to a short-circuit state. A possible trimming method can be provided.

Further, the semiconductor trimming device includes a first trimming means for shifting from a short-circuit state to an open state,
A circuit in which a second trimming means that shifts from an open state to a short-circuit state and requires less current for state transition than the first trimming means is connected in parallel to a semiconductor resistance element having a predetermined resistance value, and further connected in parallel. And the first trimming means may be connected in series.

Here, the second trimming means is shifted from the open state to the short-circuit state, and a current is applied to keep the first trimming means in the short-circuit state. Circuit trimming for shifting to a state and, if necessary, circuit trimming for shifting to an open state by applying a current for shifting the first trimming means from a short-circuit state to an open state. A possible trimming method can be provided.

The present invention also constitutes a semiconductor trimming device capable of shifting from a predetermined resistance value to a plurality of resistance values. It is connected in series with a plurality of trimming means with different current values required to transition from a short-circuit state to an open state,
Each trimming means has a configuration in which semiconductor resistance elements having a predetermined resistance value are connected in parallel.

Further, according to the trimming method of the present invention, the current values required for shifting from the short-circuit state to the open state are different.
A plurality of trimming units are connected in series, and each trimming unit is connected to a semiconductor trimming device having a configuration in which semiconductor resistance elements having a predetermined resistance value are connected in parallel. A current for changing a state of at least one or more trimming units is provided. Is applied to shift to a state having a required resistance value.

Further, it is preferable to use a Zener zap diode as the trimming means for shifting from the open state to the short-circuit state, and to use a polysilicon fuse or an aluminum fuse as the trimming means for shifting from the short-circuit state to the open state.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a semiconductor trimming apparatus and a trimming method according to the present invention will be described.
This will be described with reference to FIGS. FIG. 1 shows the first embodiment, and FIG. 2 shows the second embodiment.
FIG. 3 is a circuit diagram and an equivalent circuit diagram of the third embodiment.

First, the circuit configuration of a semiconductor trimming apparatus 11 according to the first embodiment is, as shown in FIG. 1A, a series connection of a fuse 1 and a resistor 3 between pads 4a and 4b. , And an antifuse 2 is provided in parallel with this. Although a fuse 1, an anti-fuse 2, a resistor 3, and pads 4a and 4b are shown as trimming elements, this semiconductor device also includes elements such as a bipolar transistor, a MOS transistor, a resistor, and a capacitor. This semiconductor trimming device is used for trimming a circuit formed by connecting these elements. Generally, polysilicon and aluminum are used for the fuse 1 and Zener is used for the anti-fuse 2. Zap diodes are used.

Next, the operation will be described. FIG. 1 (a
If the state of -1) is the initial state, its equivalent circuit is as shown in FIG. 1 (b-1). That is, fuse 1
Is in a short-circuit state and the anti-fuse 2 is in an open state, so that the resistor 3 is connected between the pads 4a and 4b.

Incidentally, the resistance 3 is generally 10 kΩ to 50 kΩ.
It is about 0 kΩ. The resistance value of the fuse is also added to the resistance 3 in the circuit configuration, but in practice, this resistance value is as small as about 100Ω and can be ignored. Further, the current for shifting the fuse 1 from the short-circuit state to the open state is set to a smaller value than the current for shifting the anti-fuse 2 from the open state to the short-circuit state.

Next, when the fuse 1 is opened, the fuse 1 shown in FIG.
(A-2) is a circuit configuration, and its equivalent circuit is shown in FIG.
-2). The current required to open the fuse 1 is, for example, 5 mA, and the anti-fuse 2 does not cause a state transition with this current. In this state, the fuse 1 is opened and the anti-fuse 2 is kept open, so that the pad 4 is opened as shown in FIG.
a, 4b, that is, the semiconductor trimming device is in an open state.

Further, when the antifuse 2 is short-circuited, FIG. 1A-3 shows a circuit configuration, and an equivalent circuit thereof is as shown in FIG. 1B-3. The current required to short the antifuse 2 is, for example, 10 mA,
As shown in FIG. 1B-3, between the pads 4a and 4b, that is, the semiconductor trimming device is in a short-circuit state.

As described above, the semiconductor trimming device 11 shown in FIG. 1 can change its state to two different states according to the circuit characteristics, that is, a predetermined resistance value → open state → short state. .

Next, as shown in FIG. 2A, the circuit configuration of the semiconductor trimming device 12 according to the second embodiment is such that an antifuse 2 and a resistor 3 are connected in parallel between pads 4a and 4b. A connection and a fuse 1 are provided in series with the connection. Although a fuse 1, an anti-fuse 2, a resistor 3, and pads 4a and 4b are shown as trimming elements,
This semiconductor device also includes elements such as a bipolar transistor, a MOS transistor, a resistor, and a capacitor, and is used for trimming a circuit formed by connecting these elements. As in the first embodiment, polysilicon and aluminum are used, and a Zener zap diode is used as the antifuse 2.

Next, the operation will be described. FIG.
If the state of -1) is the initial state, its equivalent circuit is as shown in FIG. 2 (b-1). That is, fuse 1
Is in a short-circuit state and the anti-fuse 2 is in an open state, so that the resistor 3 is connected between the pads 4a and 4b.

Incidentally, the resistance 3 is generally 10 kΩ to 50 kΩ.
It is about 0 kΩ. The resistance value of the fuse is also added to the resistance 3 in the circuit configuration. However, since this resistance value is actually as small as about 100Ω, it can be ignored as in the first embodiment. is there. Also, fuse 1
Is set to a larger value than the current that changes the antifuse 2 from the open state to the short circuit state.

Next, when the antifuse 2 is short-circuited, FIG. 2A-2 shows a circuit configuration, and an equivalent circuit thereof is as shown in FIG. 2B-2. The current required to short-circuit the anti-fuse 2 is, for example, 5 mA, and the fuse 1 does not cause a state transition with this current. In this state, the antifuse 2 is short-circuited, and the fuse 1 remains in the short-circuited state. Therefore, as shown in FIG. 2B-2, between the pads 4a and 4b, that is, the semiconductor trimming device 1
2 is short-circuited.

Further, when the fuse 1 is opened, the operation shown in FIG.
(A-3) shows a circuit configuration, and an equivalent circuit thereof is shown in FIG.
-3). The current required to open the fuse 1 is, for example, 10 mA, as shown in FIG.
As shown in FIG. 7, the portion between the pads 4a and 4b, that is, the semiconductor trimming device is open.

As described above, the state of the semiconductor trimming device 12 shown in FIG. 2 can be shifted to two different states according to the circuit characteristics, that is, the predetermined resistance value → short state → open state. .

Next, as shown in FIG. 3 (a-1), the circuit configuration of the semiconductor trimming device 13 according to the third embodiment is such that a fuse 1a and a resistor 3 are provided between pads 4a and 4b.
a, fuse 1b and resistor 3b, fuse 1c and resistor 3c
Are connected in series and connected in parallel.

Here, the current required to change the state of the fuses 1a, 1b, and 1c is different. For example, the current required to change the state of the fuse 1a is 3 mA, and the current required to change the state of the fuse 1b is 3 mA. Is required to be 6 mA, and the current required to shift the state of the fuse 1c is 9 mA or the like. Fuses with different current values for shifting states can be easily realized by changing the width of the fuse itself.

Fuse 1a, 1
b, 1c, resistors 3a, 3b, 3c and pads 4a, 4b are shown. This semiconductor device also includes elements such as a bipolar transistor, a MOS transistor, a resistor, and a capacitor, and is formed by connecting these elements. As in the first embodiment, polysilicon and aluminum are generally used for the fuses 1a, 1b, and 1c.

Next, the operation will be described. FIG.
Assuming that the state of -1) is the initial state, the equivalent circuit is as shown in FIG. That is, fuse 1
a, 1b and 1c are all in a short-circuit state, and the pads 4a and 4c
There is a short circuit between b.

Strictly speaking, the resistance values of the fuses 1a, 1b and 1c are R1a, R1b and R1c, respectively,
Assuming that the resistance values of b and 3c are R3a, R3b and R3c, respectively, the resistance r1 between the pads 4a and 4b is r1 = [(R1a × R3a) / (R1a + R3a) + (R1b × R3b) / (R1b + R3b) + (R1c × R3c) / (R1c + R3c)] ≒ R1a + R1b + R1c (1) However, fuses 1a, 1b, and 1c are 10
Although it has a resistance value of about 0Ω, the resistances 3a, 3b and 3c are generally in the range of about 10 kΩ to 500 kΩ, and r1 is extremely small as compared with this.

Next, when a current required to open the fuse 1a, for example, 3 mA, is applied, the fuse 1b,
The state of 1c does not change, and only the fuse 1a shifts from the short-circuit state to the open state. In this case, FIG. 3A-2 shows a circuit configuration, and its equivalent circuit is as shown in FIG. 3B-2. Therefore, the resistance r2 between the pads 4a and 4b is r2 = [R3a + (R1b.times.R3b) / (R1b + R3b) + (R1c.times.R3c) / (R1c + R3c)] cR3a (2)

Further, when a current required to open the fuse 1b, for example, 6 mA is applied, the state of the fuse 1c does not change, and the fuse 1b shifts from the short-circuit state to the open state. In this case, FIG. 3A-3 shows a circuit configuration, and its equivalent circuit is as shown in FIG. 3B-3.
Therefore, the resistance r3 between the pads 4a and 4b is as follows: r3 = [R3a + R3b + (R1c × R3c) / (R1c + R3c)] ≒ R3a + R3b (3)

Further, when a current required to open the fuse 1c, for example, 9 mA is applied, the fuse 1c shifts from the short-circuit state to the open state. In this case, FIG.
-4) is a circuit configuration, and its equivalent circuit is shown in FIG.
4). Therefore, the resistance r4 between the pads 4a and 4b is as follows: r4 = R3a + R3b + R3c (4)

As described above, the semiconductor trimming device 13 shown in FIG. 3 changes its state from a short-circuit state to a resistance value r1.
→ Resistance value r2 → Resistance value r3 It is possible to shift to three different states according to the circuit characteristics. In the third embodiment, three stages are stacked, but it goes without saying that the number of stages may be further increased. In addition, the last stage is only a fuse, and this fuse is changed from a short circuit state to an open state,
An open state function may be added to the semiconductor trimming device 13.

It is to be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that any circuit configuration that embodies the technical idea can be adopted within the scope of the present invention.

[0043]

As described above in detail, according to the semiconductor trimming device of the present invention, it is possible to reduce the number of pads for realizing a plurality of trimming states.
Therefore, the area of the semiconductor integrated circuit requiring trimming can be reduced, and the circuit adjustment by the trimming means can be applied to a semiconductor device in which the number of adjustment bits is conventionally restricted from the number of measurable pins of the tester. Become like

[Brief description of the drawings]

FIG. 1 is a circuit diagram and an equivalent circuit diagram showing a first embodiment of a semiconductor trimming device according to the present invention.

FIG. 2 is a circuit diagram and an equivalent circuit diagram showing a second embodiment of the semiconductor trimming device according to the present invention.

FIG. 3 is a circuit diagram and an equivalent circuit diagram showing a third embodiment of a semiconductor trimming device according to the present invention.

FIG. 4 is a circuit diagram showing a configuration of a conventional semiconductor trimming device.

FIG. 5 is a circuit diagram showing another configuration of a conventional semiconductor trimming device.

[Explanation of symbols]

1, 1a, 1b, 1c: fuse, 2, 2a, 2b: antifuse, 3, 3a, 3b, 3c: resistor, 4a, 4
b, 4c pad, 11, 12, 13, 14, 15 ... semiconductor trimming device

Claims (10)

[Claims] 1. A semiconductor trimming device capable of moving from a predetermined resistance value to any of a short-circuit state and an open state. 2. The method according to claim 1, wherein the predetermined resistance is 1 kΩ or more and 10 kΩ or more.
0 kΩ or less, and the short-circuit state is a state in which the resistance value is one digit or more lower than the predetermined resistance value, and the open state is one digit number than the predetermined resistance value. The semiconductor trimming device according to claim 1, wherein the semiconductor trimming device has a high resistance value. 3. A circuit in which first trimming means for shifting from a short-circuit state to an open state and a semiconductor resistance element having a predetermined resistance value are connected in series, and second trimming means for shifting from an open state to a short-circuit state. Are connected in parallel, and the current required for the first trimming means to transition from the short-circuit state to the open state is required for the second trimming means to transition from the open state to the short-circuit state. 2. The semiconductor trimming device according to claim 1, wherein the current is smaller than a predetermined current. 4. The semiconductor trimming device according to claim 3, wherein said first trimming means is shifted from a short-circuit state to an open state, and said current is large enough to keep said second trimming means in an open state. Circuit trimming to shift from a predetermined resistance value in an initial state to an open state, and, if necessary, applying a current of a magnitude to shift the second trimming means from an open state to a short-circuit state. And performing circuit trimming for shifting to a short-circuit state. 5. A circuit in which a first trimming means for shifting from a short-circuit state to an open state, a second trimming means for shifting from an open state to a short-circuit state, and a semiconductor resistor having a predetermined resistance are connected in parallel. Are connected in series, and the current required for the first trimming means to transition from the short-circuit state to the open state is required for the second trimming means to transition from the open state to the short-circuit state. 2. The semiconductor trimming device according to claim 1, wherein the current is larger than the current. 6. The semiconductor trimming device according to claim 5, wherein said second trimming means is shifted from an open state to a short-circuit state, and said first trimming means is kept short-circuited. Circuit trimming to shift from a predetermined resistance value in an initial state to a short-circuit state, and further, if necessary, applying a current to shift the first trimming means from a short-circuit state to an open state to open the circuit. Circuit trimming for shifting to a state. 7. A semiconductor trimming device, wherein a predetermined resistance value can be shifted to a plurality of resistance values by trimming means for shifting from a short-circuit state to an open state. 8. A plurality of trimming means having different current values required for shifting from a short-circuit state to an open state are connected in series, and a semiconductor resistor having a predetermined resistance value is connected in parallel to each of the trimming means. The semiconductor trimming device according to claim 7, wherein the semiconductor trimming device is provided. 9. The semiconductor trimming device according to claim 8, wherein a required resistance value is changed by applying a current that changes a state of at least one of the plurality of trimming units. A trimming method characterized by causing a transition to a holding state. 10. A zener zap diode as one of a polysilicon fuse and an aluminum fuse is used as trimming means for shifting from a short-circuit state to an open state, and a zener zap diode is used as trimming means for shifting from an open state to a short-circuit state. The semiconductor trimming apparatus according to any one of claims 1, 2, 3, 5, 5, 7, and 8, characterized by using: