JPH06216253A - Trimming device - Google Patents

Abstract

PURPOSE:To operate a circuit to be trimmed in an initial state by trimming it and then again trimming it. CONSTITUTION:A trimming circuit 11 having first trimming means (fuse 12) for transferring both ends from a short-circuiting state to an open state and second trimming means (anti-fuse 13) for transferring both ends from an open state to a shortcircuiting state to be connected in series with the fuse 12 is connected in parallel with a circuit 51 to be trimmed. Or, a plurality of the circuits 11 are connected in parallel with the circuit 51 to be trimmed. Or, a trimming circuit in which first trimming means is connected in parallel with the second trimming means is connected in series with the circuit to be trimmed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trimming device used for semiconductor integrated circuits.

[0002]

2. Description of the Related Art In a semiconductor integrated circuit, a circuit characteristic value is set within a predetermined range by trimming resistors and capacitors. Examples of the trimming method include a method of electrically blowing a metal fuse or a polysilicon fuse used as a means for shifting from a short-circuited state to an open state, or a method of blowing a fuse by irradiating laser light.

On the other hand, as a means for shifting from the open state to the short-circuited state, there is one using laser light. This means irradiates a portion to which two metal layers separated by an insulating film are connected to each other with laser light to short-circuit.
Alternatively, a method of irradiating laser light between metal wirings formed with a narrow interval to short-circuit each other, or a short section is set to an intrinsic state or a high resistance state, and a high concentration impurity is introduced into another region. A method of irradiating the formed polysilicon intrinsic region or high-resistance region with laser light to diffuse impurities from the high-concentration region to the intrinsic region to short-circuit has been proposed.

A method using a Zener diode has also been proposed. In this method, a reverse voltage equal to or lower than the breakdown voltage is normally applied to the Zener diode to open it. When trimming is required, so-called zener zap is performed in which an overcurrent is applied in the opposite direction to destroy the zener diode.

[0005]

However, in any of the methods described above, trimming is performed by breaking a fuse or a Zener diode. Therefore, if the trimming target circuit is trimmed,
The trimmed element cannot be returned to the initial state again. Therefore, the trimming target circuit cannot be operated again. In this way, the circuit contents can be modified by trimming only once.

An object of the present invention is to provide a trimming device capable of returning to an initial state after trimming a circuit to be trimmed.

[0007]

The present invention is a trimming device made to achieve the above object. That is, the first trimming device includes first trimming means for shifting both ends from the short-circuited state to the open state and one for shifting both ends from the open state to the short-circuited state.
The trimming circuit composed of the second trimming means connected in series to the trimming means is connected in parallel to the trimming target circuit. Alternatively, the plurality of trimming circuits are connected in parallel to the trimming target circuit.

Alternatively, as the second trimming device,
A trimming circuit is configured by connecting in parallel a first trimming means for shifting both ends from a short-circuited state to an open state and a second trimming means for shifting both ends from an open-state to a short-circuited state, which is to be trimmed. It is connected in series to the circuit. Alternatively, the plurality of trimming circuits are connected in series and are connected in series to the trimming target circuit.

[0009]

In the first trimming device, the trimming is performed by shifting the second trimming means that shifts both ends from the open state to the short-circuited state to the ON state. Then, the trimming target circuit can be returned to the initial state by shifting the first trimming means for shifting both ends from the short circuit state to the open state to the OFF state. Further, by providing a plurality of trimming circuits in parallel with the trimming target circuit, the trimming of the trimming target circuit and the transition to the initial state can be repeated.

In the second trimming device, the first trimming means for shifting both ends from the short-circuited state to the open state is O.
Trimming is performed by shifting to the FF state. Then, the trimming target circuit can be returned to the initial state by shifting the second trimming means that shifts both ends from the open state to the short circuit state to the ON state. Further, by connecting the plurality of trimming circuits in series and connecting the trimming target circuit in series, the trimming of the trimming target circuit and the transition to the initial state can be repeated.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the first invention will be described with reference to the circuit configuration diagram of FIG. As shown in the figure, the trimming circuit 11 is
A first trimming means (hereinafter referred to as a fuse 12) that shifts both ends from a short-circuited state to an open state and a second trimming means (hereinafter referred to as an anti-fuse 13) that shifts both ends from an open state to a short-circuited state are connected in series. Configured to be connected to. The trimming circuit 11 is connected in parallel to the trimming target circuit 51. Here, the trimming target circuit 51 includes elements such as resistors and capacitors. The trimming device 10 is configured as described above.

The operation of the trimming device 10 having the above structure will be described. In the initial state of the trimming target circuit 51, the trimming target circuit 51 operates because the antifuse 13 in the trimming portion is in the OFF state. next,
The case of trimming will be described. First, the antifuse 13 is transferred to the ON state (short circuit state). As a result, the antifuse 13, which is the trimming element portion, is turned on, so that the trimming target circuit 51 is deactivated. Then, in order to return the trimming target circuit 51 to the initial state, since the anti-fuse 13 is connected in series to the fuse 12, the fuse 12 shifts from the ON state (short circuit state) to the OFF state (open state). As a result, the trimming element portion returns to the same OFF state as the initial state. As a result, the trimming target circuit 51 can be operated again.

Therefore, after the circuit characteristics are corrected by the trimming described in the above embodiment so that the circuit characteristics are within a predetermined range, for example, when the circuit characteristics change due to a change with time or a change in conditions in the manufacturing process, For example, by turning off the fuse 12, the trimming target circuit 51 can be easily returned to the initial state.

Next, another embodiment of the first invention is shown in FIG.
The circuit configuration diagram will be described. The same components as those described with reference to FIG. 1 are designated by the same reference numerals. As shown in the figure, the trimming device 20 includes a trimming target circuit 51 and a trimming circuit group 21 connected in parallel to the trimming target circuit 51. The trimming circuit group 21 is composed of a plurality of (for example, n) trimming circuits 11 similar to those described in the first embodiment of the present invention, which are connected in parallel. Each trimming circuit 11
A first trimming means (hereinafter referred to as a fuse 12) that shifts both ends from a short-circuited state to an open state and a second trimming means (hereinafter referred to as an anti-fuse 13) that shifts both ends from an open state to a short-circuited state are connected in series. It is connected to the. The trimming target circuit 51 includes elements such as resistors and capacitors.

The operation of the trimming device 20 having the above structure will be described. In the initial state of the trimming target circuit 51, each antifuse 13 in the trimming portion is in the OFF state (open state), so that the trimming target circuit 51 operates. Next, a case where trimming is performed will be described. First, one of the antifuses 13
(13a) is transferred to the ON state (short circuit state). As a result, the antifuse 13a, which is the trimming element portion, is turned on, so that the trimming target circuit 51 is deactivated. Then, in order to return to the initial state, the antifuse 13a is connected in series to the fuse 12 (12a) of the trimming circuit 11 (11a).
By shifting the fuse 12a from the ON state (short circuit state) to the OFF state (open state), the trimming element portion returns to the same OFF state as the initial state. As a result, the trimming target circuit 51 can be operated again.

When trimming is performed again, one of the antifuses 13 (13b) other than the trimmed antifuse 13a is turned on. As a result, the antifuse 13b, which is the trimming element portion, is turned on, so that the trimming target circuit 5
1 becomes inactive. Then, in order to return to the initial state, the antifuse 13b is operated by the trimming circuit 11 (11
Since the fuse 12 (12b) of b) is connected in series, the trimming element portion returns to the same OFF state as the initial state by shifting the fuse 12b from the ON state to the OFF state. As a result, the trimming target circuit 51 can be operated again.

Therefore, as many trimming circuits 11 as the number (for example, n in the case of the above-mentioned other embodiment) are provided,
It is possible to perform trimming, and it is also possible to return the trimming target circuit 51 to the initial state. That is, it is possible to repeat the n times the trimming target circuit 51 is brought into the non-operating state or the operating state.

Next, an embodiment of the second invention will be described with reference to the circuit configuration diagram of FIG. The same components as those described with reference to FIG. 1 are designated by the same reference numerals. As shown in the figure, the trimming circuit 31 is a first trimming means (hereinafter referred to as a fuse 12) that shifts both ends from a short-circuited state to an open state.
And a second trimming means (hereinafter referred to as an antifuse 13) for shifting both ends from an open state to a short circuit state are connected in parallel. Trimming circuit 3 above
1 is connected in series to the trimming target circuit 51. Here, in the trimming target circuit 51,
Elements such as resistors and capacitors are also included. The trimming device 30 is configured as described above.

The operation of the trimming device 30 having the above structure will be described. In the initial state of the trimming target circuit 51, the trimming target fuse 12 is in the ON state (short-circuited state), so that the trimming target circuit 51 operates.
Next, a case where trimming is performed will be described. First, the fuse 12 is transferred to the OFF state (open state). At this time, since the antifuse 13 is connected in parallel with the fuse 12 and is in the OFF state (open state), the trimming target circuit 51 is in the inoperative state.
Next, a method of returning the trimming target circuit 51 to the operating state will be described. First, turn off the antifuse 13
The state (open state) shifts to the ON state (short circuit state). As a result, the trimming element portion has the same O as in the initial state.
Since the circuit returns to the N state, the trimming target circuit 51 can be operated again.

Therefore, even by the trimming described in the embodiment of the second aspect of the invention, after the circuit characteristic is corrected so as to be within the predetermined range, the circuit characteristic is changed due to, for example, a change with time or a change in the condition in the manufacturing process. When it changes, the trimming target circuit 51 can be easily returned to the initial state by turning on the antifuse 13.

Next, another embodiment of the second invention is shown in FIG.
The circuit configuration diagram will be described. The same components as those described with reference to FIG. 1 are designated by the same reference numerals. As shown in the figure, the trimming device 40 includes a trimming target circuit 51 and a trimming circuit group 41 connected in series to the trimming target circuit 51. Trimming circuit group 4
1 comprises a plurality of (for example, n) trimming circuits 31 connected in series, which are similar to those described in the second embodiment of the present invention. Each trimming circuit 31 has a first trimming means (hereinafter referred to as a fuse 12) that shifts both ends from a short-circuited state to an open state, and a second trimming means (hereinafter an anti-fuse 13) that shifts both ends from an open state to a short-circuited state. And) are connected in parallel. The trimming target circuit 51 includes elements such as resistors and capacitors.

The operation of the trimming device 40 having the above structure will be described. In the initial state of the trimming target circuit 51, the fuse 12 in the trimming portion is in the ON state (short-circuit state), so the trimming target circuit 51 operates. Next, a case where trimming is performed will be described. First, one fuse 12 (12a) of the plurality of fuses 12 is OF
Transition to F state (open state). At this time, the antifuse 13 forming the trimming circuit 31 (31a)
Since (13a) is connected in parallel to the fuse 12a and is in the OFF state (open state), the trimming target circuit 51 is in the non-operating state. Next, a method of returning the trimming target circuit 51 to the operating state will be described. First, the antifuse 13a is switched from the OFF state (open state) to the ON state (short circuit state).
As a result, the trimming element portion returns to the ON state which is the same as the initial state, so that the trimming target circuit 51 can be operated again.

When the trimming is performed again, for example, one fuse 12 (12b) other than the trimmed fuse 12a is shifted to the OFF state. At this time, the antifuse 13 (13b) forming the trimming circuit 31 (31b) is connected in parallel to the fuse 12b and is in the OFF state, so that the trimming target circuit 51 is in the inoperative state. . Then, in order to return the trimming target circuit 51 to the initial state, the antifuse 13b is shifted from the OFF state to the ON state. As a result, the trimming element portion returns to the ON state which is the same as the initial state, so that the trimming target circuit 51 can be operated again.

Therefore, it becomes possible to perform the trimming by the number of the trimming circuits 31 provided (for example, n times in the case of the other embodiment of the second invention), and then the trimming target circuit 51 is initialized. It is also possible to return to the state. That is, it is possible to repeat the n times the trimming target circuit 51 is brought into the non-operating state or the operating state.

[0025]

As described above, according to the inventions of claims 1 and 2, the second trimming means (anti-fuse) for turning both ends from the open state to the short-circuited state is turned on.
Trimming can be performed by shifting to the state.
And, the first that shifts both ends from the short-circuited state to the open state
The trimming means (fuse) can be returned to the initial state by shifting it to the OFF state. Further, according to the inventions of claims 3 and 4, the first trimming means (fuse) for shifting both ends from the short-circuited state to the open state is turned off.
Trimming can be performed by shifting to the state.
Then, the second that shifts both ends from the open state to the short-circuited state
The trimming means (anti-fuse) can be returned to the initial state by shifting it to the ON state. Therefore,
Since it is possible to return to the initial state after trimming, which was impossible in the past, it is possible to improve the yield of the semiconductor integrated circuit. Further, the application field of the semiconductor integrated circuit can be expanded.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of the first invention.

FIG. 2 is a circuit configuration diagram of another embodiment of the first invention.

FIG. 3 is a circuit configuration diagram of an embodiment of the second invention.

FIG. 4 is a circuit configuration diagram of another embodiment of the second invention.

[Explanation of symbols]

10 Trimming Device 11 Trimming Circuit 12 Fuse (First Trimming Means to Move Both Ends from Shorted to Open) 13 Anti-Fuse (Second Trimming Means to Move Both Ends to Shorted from Open) 20 Trimming Device 21 Trimming Circuit group 30 Trimming device 31 Trimming circuit 40 Trimming device 41 Trimming circuit group 51 Trimming target circuit

Claims (4)

[Claims] 1. A first trimming means for shifting both ends from a short circuit state to an open state, and a first trimming means for shifting both ends from an open state to a short circuit state, which is connected in series to the first trimming means. A trimming device comprising a trimming circuit including the second trimming means connected in parallel to a trimming target circuit. 2. The trimming device according to claim 1, wherein a plurality of the trimming circuits are connected in parallel to the trimming target circuit. 3. A first trimming means for shifting both ends from a short circuit state to an open state, and a first trimming means for shifting both ends from an open state to a short circuit state, which is connected in parallel to the first trimming means. 2. A trimming device comprising a trimming circuit including the trimming means 2 connected in series to a trimming target circuit. 4. The trimming device according to claim 3, wherein a plurality of the trimming circuits are connected in series to the trimming target circuit.