JPH0637247A - Semiconductor device - Google Patents

Abstract

PURPOSE:To contrive to give such a self-correcting function as to confine the element characteristics of an element within a previously determinded constant standard to a semiconductor device without making the processing operation of the device interrupt even in the case where the element characteristics of the element constituting the device are fluctuated during the operation of the device. CONSTITUTION:A semiconductor device 10 having an element characteristic self-correcting function is constituted of an element characteristic adjusting circuit 3, which is connected with a fundamental circuit 2 of an element set as to satisfy previously determined characteristics in parallel to the circuit 2 and adjusts the element characteristics of the circuit 2, a decision circuit 5, which has the same constitution as that of the circuit 2 and decides the state of the element characteristics in responce to the output of a reference circuit which constitutes the circuit 2 and detects the state of the element characteristics, and a control circuit 6, which controls at least one side of the circuits 2 and 3 in responce to the output of the circuit 5. Thereby, such a self-correcting function as to confine the element characteristics within a constant standard can be given to the device without making the processing operation of the device interrupt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a semiconductor device having a self-correction function with respect to variations in element characteristics of the semiconductor device.

[0002]

2. Description of the Related Art In recent years, semiconductor integrated circuits are required to be highly integrated and highly accurate. However, variations in element characteristics due to controllability problems in process steps or temperature changes,
Fluctuations in device characteristics due to the influence of changes over time have an adverse effect on the accuracy.

Therefore, it is unavoidable that an error or malfunction occurs in the operation of the semiconductor device, the function of the semiconductor device is stopped, or an incorrect result is output. Conventionally, as a method of correcting and adjusting the variation in the element characteristics of the semiconductor device, for example, while the semiconductor device is in a manufacturing process before it is completed as a product, the element characteristics of the semiconductor device are initially designed. Whether it is exhibited as it is or not is detected by some method, and if there is a difference from the initial design, an adjustment element is added to the semiconductor device separately, or the semiconductor device is used for adjustment in advance. It is generally practiced to perform adjustment by a so-called trimming method in which fuses that are arranged are cut, and to perform adjustment and correction so that predetermined element characteristics are exhibited.

Further, after the semiconductor device is completed,
If the element characteristics of the semiconductor device are different from the initial design, the difference is corrected by externally attaching an adjusting element, such as a resistor or a capacitor, to the product in which the semiconductor device is mounted. Has also been done. However, such a conventional correction method is temporary, and when the element characteristics of the semiconductor device are changed again after executing the above-described correction operation, trimming is performed again or the element is external to the LSI. Since it is necessary to attach a circuit for correction, the adjustment work becomes complicated, and at the same time, the function of the semiconductor device has to be stopped during the adjustment operation.

Therefore, in the conventional semiconductor device, it is necessary to temporarily suspend the operation of the semiconductor device such as the LSI and execute the operation for re-correction every time the element characteristic changes. There has been a problem that the operation efficiency and reliability of semiconductor devices such as LSIs are significantly reduced.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems in the prior art, and even when the element characteristics of the elements constituting the semiconductor device change during the operation of the semiconductor device, It is intended to provide a semiconductor device having a self-correction function that keeps the element characteristics of the element within a predetermined standard without interrupting the processing operation of the semiconductor device.

[0007]

In order to achieve the above-mentioned object, the present invention adopts the technical constitution as described below. That is, a semiconductor device having a self-correction function for self-correcting its own element characteristics, and specifically, a basic circuit composed of elements set to satisfy predetermined characteristics, and the basic circuit An element characteristic adjusting circuit connected in parallel with the basic circuit for adjusting the element characteristic, a reference circuit having the same configuration as the basic circuit and detecting a state of an element characteristic forming the basic circuit, the reference circuit Element characteristic comprising a determination circuit for determining the state of the element characteristic in response to the output of the control circuit and a control circuit for controlling at least one of the basic circuit and the adjustment circuit in response to the output of the determination circuit. A semiconductor device having a self-correction function.

[0008]

Since the semiconductor device according to the present invention has the above-described technical structure, the element characteristics of each element (basic circuit) of the semiconductor device are constantly monitored by the reference circuit, In the determination circuit, it is determined whether or not the element characteristics of the element deviate from a predetermined predetermined element characteristic standard, and if the element characteristic deviates from the standard, or When it is determined that there is a possibility of deviation, the control circuit responds to the output of the determination circuit to turn ON / OFF the plurality of elements that form the basic circuit and the element characteristic adjusting circuit. The control operation is performed so that the element characteristic of the element is adjusted to fall within a predetermined standard value.

Since the operation for exerting the self-correction function in the semiconductor device is always executed in the semiconductor device, the element characteristics can be maintained even when the semiconductor device changes with time or temperature. Is always normal, that is, it can be self-corrected so that it falls within a predetermined standard, so that it is possible to avoid the occurrence of a situation in which the processing is interrupted or a malfunction occurs during the operation of the semiconductor device. The efficiency of the processing configuration of the semiconductor device can be greatly improved, and at the same time, the reliability of the semiconductor device can be greatly improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of a semiconductor device having a self-correction function according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram for explaining the principle of a semiconductor device having a self-correction function according to the present invention, and is also a block diagram showing a configuration of a specific example of the semiconductor device according to the present invention.

That is, in FIG. 1, the semiconductor device 10 is
In the above, a basic circuit 2 composed of elements set so as to satisfy predetermined characteristics, and an element characteristic adjusting circuit for adjusting the element characteristics of the basic circuit 2 connected in parallel with the basic circuit 2 3, a reference circuit 1 having the same configuration as the basic circuit 2 for detecting the state of the element characteristic forming the basic circuit 2, and determining the state of the element characteristic in response to the output of the reference circuit 1. A semiconductor device 10 having an element characteristic self-correction function, which is composed of a determination circuit 5 for It is shown.

The structure of the elements in the semiconductor device 10 according to the present invention is not particularly limited, and a plurality of elements may be provided so that the semiconductor device 10 can exhibit the required characteristics. May be of any configuration as long as they are appropriately arranged and wired to form a predetermined arithmetic processing means. Therefore, the element in the semiconductor device according to the present invention may be composed of, for example, a bipolar transistor or a field effect transistor, and each transistor in each element is The configuration, characteristics, size, etc. may be designed arbitrarily.

However, since it is necessary to improve the efficiency of the manufacturing process of the semiconductor device, simplify the process, improve reliability, and obtain compatibility with other elements, each transistor forming the element has the same structure. It is preferable to adopt those having substantially the same characteristics. The semiconductor device 1 according to the present invention
At 0, the basic circuit 2 is a circuit that constitutes a basic processing means for exhibiting the original operation of the semiconductor device 10, and the reference circuit 1 is the basic circuit 2. The element characteristic of the basic circuit 2 can be determined by applying a predetermined reference current to the reference circuit 1 and measuring the voltage generated at both ends of the reference circuit 1. It is to determine whether there is.

That is, the reference circuit 1 functions as a certain kind of sensor, and basically, if the element characteristics of the basic circuit 2 change due to temperature change or aging, The self-correction function is realized based on the fact that the voltage representative of the element characteristic output from the reference circuit 1 having the same configuration as the basic circuit 2 also changes.

Therefore, it is necessary that the basic circuit 2 and the reference circuit 1 are constructed so that the element characteristics of the elements change at the same ratio. Both elements have the same configuration. or,
In the semiconductor device 10 according to the present invention, the basic circuit 1 and the element characteristic adjusting circuit 3 constitute the arithmetic processing means 4 for exhibiting the element characteristic in the semiconductor device 10. The determination circuit 5 and the control circuit 6 are arranged between the arithmetic processing means 4 and the reference circuit 1.

The structure of the semiconductor device 10 according to the present invention is shown in FIG.
More specifically, in FIG. 2, the element characteristic of the semiconductor device 10 according to the present invention is defined as, for example, conductance, and the conductance is controlled so as to be within a predetermined standard range. It is assumed that the self-correction function circuit of is configured. The case where the basic circuit 2, the element characteristic adjusting circuit 3, and the reference circuit 1 are all composed of a plurality of elements is shown. Particularly, in the present specific example,
The basic circuit 2 has two elements 21 and 22 arranged in parallel, and the reference circuit 1 also has two elements 11 and 12 arranged in parallel.

The elements of the basic circuit 2 and the reference circuit 1 may be one, or may be composed of a plurality of two or more. However, the number of elements and the array shape of both circuits must be the same. Furthermore, when a plurality of elements are used in both circuits, they may be arranged in series or may be arranged in parallel.

However, in order to exert the self-correction function of the present invention, the direction of adjustment and correction of the element characteristic is adjusted in either the increasing direction or the decreasing direction of the element characteristic value. Since it is preferable that the elements can be corrected, it is desirable that the element groups are arranged in parallel. Element groups 31, 32 ... 3n-1 and 3n-1 that constitute the element characteristic adjusting circuit 3 according to the present invention
2 has a parallel arrangement as shown in FIG. 2, and the conductance of the element characteristic adjusting circuit 3 can be adjusted to an appropriate value by turning ON / OFF any of the element groups.

The elements 31, 32, ... 3n-1, 3n-1 arranged in the element characteristic adjusting circuit 3 have a different configuration from the elements 21, 22 constituting the basic circuit 2. It is something. Therefore, for example, each of the elements 31, 32, ...
−1 is made different in size, and in order to make the size different, for example, at least one of the channel length and the channel width of the transistor forming the element is set to each of the elements 21 and 22 forming the basic circuit. It can be configured to have a different channel length or channel width.

As an example thereof, the elements 31, 32 ... 3n-1, 3 arranged in the element characteristic adjusting circuit 3 are arranged.
The conductance of n−1 is 1/2 (n−) of the conductance of each of the elements 21 and 22 that constitute the basic circuit 2.
It is configured to be 1). Where n
Shall be 2 or 2 or more.

In this specific example, the element groups 31, 32, ...
The number of n-1 is not particularly limited, but it can be arbitrarily determined according to the number of elements forming the basic circuit 2. In the concrete example of FIG. 2, the basic circuit 2
Is composed of two elements 21 and 22, it is preferable that at least two elements are arranged for adjustment in the element characteristic adjusting circuit 3.

More specifically, in the element characteristic adjusting circuit 3, the elements 21 and 22 constituting the basic circuit 2 are included.
Is an element having a conductance that is half or less than the conductance characteristic of
By adopting the element configuration, the element characteristic adjusting circuit 3
It is possible to finely adjust the conductance characteristic of.

Therefore, the larger the number of elements in the element characteristic adjusting circuit 3, the finer the element characteristics can be adjusted. For example, the conductances of the elements 21, 22, 11, 12 used in the basic circuit 2 and the reference circuit 1 are set to 1
In this case, if the element forming the element characteristic adjusting circuit 3 is n
When the number of the elements is, the conductance of each of the elements is
1 / 2,1 / ² 2, 1/2 ^3, which is constituted as a · · · 1/2 ^n-1, is arranged to further add further elements having a conductance of 1/2 ^n-1 Is.

In the present invention, by further arranging an element having a conductance of 1/2 ^n-1 further,
It is possible to match the conductance characteristic in the element characteristic adjusting circuit 3 to the same value as the conductance characteristic of the elements 21 and 22 used in the basic circuit 2. Further, in the present invention, each element used in the basic circuit 2, the element characteristic adjusting circuit 3 and the reference circuit 1 has the smallest size among the elements used in the above circuits. It is preferable that the number of the elements forming each circuit is an integral multiple of the elements of the basic unit, with the element having the above as a basic unit.

Further, the judging circuit 5 in the semiconductor device 10 according to the present invention measures the terminal voltage of the reference circuit 1, and the basic circuit 2 currently operating based on the measured voltage.
It is configured to judge the state of the element characteristics in the above and transmit the information to the control circuit 6. That is, according to the above example, when it is necessary to keep the conductance characteristic of the element within a predetermined standard value, for example, the basic circuit 2
When the conductance of the reference circuit 1 increases, the potential difference of the reference circuit 1 decreases. Therefore, the determination circuit determines the degree of the difference and controls ON / OFF of the component elements including the element characteristic adjustment circuit 3 and the basic circuit 2. Then, by turning off the operation of the transistors, which are some elements, the conductance in the circuit 4 is adjusted to be small.

Also, since the potential difference of the reference circuit 1 increases as the conductance of the basic circuit 2 decreases, the configuration including the element characteristic adjusting circuit 3 and the basic circuit 2 by the judging circuit 5 and the control circuit 6 is increased. The conductance of the circuit 4 is adjusted to be large by controlling ON / OFF of the element and turning on the operation of a transistor which is an element in some OFF states.

The determination circuit 5 which performs the determination and control according to the level of the voltage output from the reference circuit 1
It suffices if the basic circuit 2 has a circuit capable of judging the state of the element characteristics of the basic circuit 2 at present, and the configuration thereof is not particularly limited, but an example thereof will be described below. When taking the conductance as the element characteristic of the element, when the minimum voltage value of the predetermined standard voltage level is V1 and the maximum voltage value is V2, the reference voltage level for the comparison judgment is given by the following equation. To configure.

(2 ^n-1 + m) / 2 ⁿ × V1 (2 ⁿ +2 ^n-1 -m) / 2 ⁿ × V2 Here, n is the number of the elements of the element characteristic adjusting circuit 3. 2 or more, and m = 1, 2, 3, ...
..2 ^n-1 . By setting such conditions, when the standard range of the conductance of the reference circuit 1 is converted into the potential difference when a reference current is passed through the reference circuit 1, and the potential difference is V, V1 <V <V2 As
The determination is made by setting a plurality of reference determination levels within the range determined above.

Therefore, when n = 2 and m = 1,
When a reference current is passed through the reference circuit 1, the output voltage V appearing across the reference circuit 1 is in the range of 3 / 4V1 <V <5 / 4V2, which is the reference level for performing the adjustment operation.
For example, (1) V <3 / 4V1 (2) 3 / 4V1 <V <V1 (3) V1 <V <V2 (4) V2 <V <5 / centered on the level of 1 and the level of 5 / 4V2 4V2 (5) It is possible to determine the change state of the conductance characteristic by setting the determination reference level like 5 / 4V2 <V.

Therefore, in the present invention, the judgment circuit 5
By confirming the state of change of the conductance by determining the above-mentioned determination reference level in and the region in which the voltage level output from the reference circuit 1 is included,
The control circuit 6 is driven so as to compensate the degree of change. The configuration of the control circuit 6 is not particularly limited, either of the elements arranged in the basic circuit 2 or the element characteristic adjusting circuit 3 is turned on in response to the output level of the determination circuit 5. It suffices that the control signal is supplied to the basic circuit 2 and the element characteristic adjusting circuit 3 by deciding which one is to be turned off.

The control circuit 6 preferably forms a unique logic circuit according to the element characteristic to be adjusted, and further, the number of reference levels for determination of the determination circuit 5, the basic circuit 2, and the element characteristic adjustment. Different logic circuits are assembled according to the number of elements forming the circuit 3. That is, the control circuit 6 in the semiconductor device according to the present invention, based on the information from the determination circuit 5, selects one of the elements constituting at least one of the basic circuit 2 and the element characteristic adjustment circuit 3. Is configured to control the driving state of
Further, the judging circuit 5 compares the change state of the element characteristic of the basic circuit 2 to be adjusted with the output voltage of the reference circuit 1 and a judging standard constituted by a plurality of predetermined different voltage level regions. The change state of the element characteristics of the basic circuit 2 thus determined is transmitted to the control circuit 6.

The control circuit 6 configures the basic circuit 2 and the element characteristic adjusting circuit 3 in response to the output of the judging circuit 5 in response to the element characteristic of the basic circuit 2 to be adjusted in advance. It is preferably set so as to generate a drive control pattern for each element that is being operated. FIG. 3 is a block diagram showing an example of the configurations of the determination circuit 5 and the control circuit 6 in the semiconductor device according to the present invention.

Here, T1 and T2 are MOS transistors forming the reference circuit 1, and T3 and T4 are transistors T.
MOS transistors that constitute the basic circuit 2 having the same configuration as that of T1 and T2, and T5 and T6 are MOs for adjusting the conductance.
S transistors, C1 to C4 are transistors T1 and T2
The comparators L1 to L5 in the judgment circuit 5 for comparing the potentials generated when a reference current is applied to the transistors L1 to L5 generate signals for controlling the transistors T3, T4, T5 and T6 from the outputs of the comparators of the judgment circuit 5. The control circuit 6 is composed of a logic circuit. In this embodiment, the transistors T1 and T
2, T3, T4, gate length = L, gate width = W ₁
And the gate length of the transistors T5 and T6 is L,
When the gate width = W ₂ and W ₁ = 2W ₁ , the conductances of the transistors T 5 and T 6 are
It is set to be 1/2 of 1, T2, T3 and T4.

Further, assuming that the standard of the conductance of the circuit in which the transistors T1 and T2 are connected in parallel must be in the range of V ₁ <V <V ₂ when the reference current I flows, the comparator of the decision circuit 5 Criteria reference voltage is C
5 / 4V ₂ , V ₂ , V ₁ and 3 for _{1 to} C 4 respectively
/ 4V ₁ . When the gates of the transistors T1 and T2 are pulled up to be in the ON state and the reference current I flows into the circuit configured by the transistors T1 and T2 in parallel, the voltage V that can appear at the point A is the following five types. It can be classified into states.

V <3/4 V ₁ 3/4 V ₁ <V <V
₁ V ₁ <V <V ₂ V ₂ <V <5 / 4V ₂ 5
/ 4V ₂ <V Of these five states, the conductance of the circuit constituted by the transistors T1 and T2 in parallel is within the standard value at the time, and in other cases, the conductance is corrected to a predetermined conductance. Need to get Therefore, as in the control circuit of FIG. 3, the AND circuits L1, L3, L4, L5 and the OR circuit L2 are arranged in a configuration as shown in FIG.
The respective outputs of 3, L4 and L5 are connected to the transistor T4.
These are connected to the gates of T5 and T6, respectively.

A signal from the logic circuit is directly connected to the gate of the transistor T3. By forming such a logic and holding any or all of the transistors T4, T5, T6 in the OFF state, the conductance of the circuit composed of the transistors T3, T4, T5, T6 is set to a predetermined conductance standard. Can be corrected within. The logic in FIG. 3 is structured as follows.

(Transistor) Judgment Standard T3 T4 T5 T6 V <3 / 4V₁ ○ OFF OFF OFF 3 / 4V₁<V <V₁ ○ OFF ○ OFF V₁<V <V₂ ○ ○ OFF OFF V₂<V <5 / 4V₂ ○ ○ ○ OFF 5 / 4V₂<V ○○○○ * ○ shows a state of operating according to a logic signal. Fig. 4 shows an example of the layout of the semiconductor device 10 of the present invention.
The MOS transistor in the circuit of FIG.
Parts are shown. Here, T1 and T2 are the reference MO
S transistors, T3 and T4 are transistors T1 and T2
It is a MOS transistor having the same structure as the above. Also T5, T
6 is a MOS transistor for adjusting conductance
, T1₁, T1₂Transistor T1 and T2₁, T
Two₂Transistor T2, T3₁, T3₂Is a transition
Star T3 to T4₁, T4₂Is the transistor T4
This is a group of MOS transistors configured as described above. Each tran
Dista T1₁, T1₂, T2₁, T2₂, T3₁, T3
₂, T4₁, T4₂, T5, T6 are all the same gate length
L, gate width W₂(= W₁/ 2), and all
All MOS transistors have the same shape and are arranged in the same direction.
ing. As a result, the transistor T1₁, T1₂, T
Two₁, T2₂, T3₁, T3₂, T4₁, T4 ₂, T
Improves relative accuracy of device characteristics of 5 and T6 transistors
It is possible to make it possible to perform correction with higher accuracy.

[0038]

Since the semiconductor device 10 according to the present invention has the structure as described above, even when the element characteristics of the elements constituting the semiconductor device change during the operation of the semiconductor device, It is possible to obtain a semiconductor device having a self-correction function that keeps the element characteristics of the element within a predetermined standard without interrupting the processing operation of the semiconductor device.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of a semiconductor device according to the present invention, and is also a diagram illustrating a configuration of a specific example of a semiconductor device according to the present invention.

FIG. 2 is a block diagram showing another specific example of the semiconductor device according to the present invention.

FIG. 3 is a block diagram showing a configuration example of a determination circuit and a control circuit of a semiconductor device according to the present invention.

FIG. 4 is a diagram showing a layout example of a semiconductor device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reference circuit 2 ... Basic circuit 3 ... Element characteristic adjustment circuit 4 ... Adjusted circuit 5 ... Judgment circuit 6 ... Control circuit 10 ... Semiconductor device

Claims (14)

[Claims] 1. A basic circuit composed of elements set to satisfy predetermined characteristics, an element characteristic adjusting circuit for adjusting the element characteristics of the basic circuit connected in parallel with the basic circuit, A reference circuit that has the same configuration as the basic circuit and that detects the state of element characteristics that make up the basic circuit, a determination circuit that determines the state of the element characteristics in response to the output of the reference circuit, and the determination circuit A semiconductor device having an element characteristic self-correction function, comprising a control circuit for controlling at least one of the basic circuit and the adjusting circuit in response to the output of the device. 2. The basic circuit is composed of a plurality of elements having the same structure.
The semiconductor device described. 3. The semiconductor device according to claim 2, wherein the basic circuit is configured by arranging a plurality of elements having the same configuration in parallel. 4. The semiconductor device according to claim 1, wherein the reference circuit is driven by a reference current. 5. The element characteristic adjusting circuit is configured by arranging in parallel a plurality of elements having a configuration different from that of each element forming the basic circuit. 4. The semiconductor device according to any one of 4 above. 6. The device according to claim 5, wherein the size of each element forming the element characteristic adjustment circuit is different from the size of each element forming the basic circuit. Semiconductor device. 7. The field effect transistor size of each element constituting the element characteristic adjusting circuit has at least one of a channel length and a channel width as a channel length or a channel length of each element constituting the basic circuit. The semiconductor device according to claim 6, wherein the semiconductor device is configured to have a different channel width. 8. Each element used in the basic circuit, the element characteristic adjusting circuit, and the reference circuit has an element having the smallest size among the elements used in each of the circuits as a basic unit. The semiconductor device according to any one of claims 1 to 7, wherein the number of the elements forming each of the circuits is configured to be an integral multiple of the elements of the basic unit. 9. The judgment circuit measures the terminal voltage of the reference circuit, judges the current state of element characteristics in the basic circuit based on the measured voltage, and sends the information to the control circuit. 9. The semiconductor device according to claim 1, wherein the semiconductor device is configured to transmit. 10. The control circuit controls, based on information from the determination circuit, a drive state of any of the elements constituting at least one of the basic circuit and the element characteristic adjustment circuit. The semiconductor device according to any one of claims 1 to 9, which is configured. 11. The judgment circuit compares the change state of the element characteristic of the basic circuit to be adjusted with a judgment reference composed of an output voltage of the reference circuit and a predetermined plurality of different voltage level regions. 10. The semiconductor device according to claim 9, wherein the semiconductor device is configured so as to make a judgment and transmit the judged change state of the element characteristic of the basic circuit to the control circuit. 12. The control circuit configures the basic circuit and the element characteristic adjusting circuit in response to the output of the determination circuit in response to the element characteristic of the basic circuit to be adjusted in advance. 12. The semiconductor device according to claim 11, wherein the semiconductor device is set so as to generate a drive control pattern for each element. 13. The elements used in the basic circuit, the element characteristic adjusting circuit and the reference circuit are all arranged in the same direction with respect to the direction of current flow. The semiconductor device according to any one of claims 1 to 12. 14. The size of each element forming the element characteristic adjusting circuit is set to be 1/2 or less of the size of each element forming the basic circuit. The semiconductor device according to any one of claims 1 to 12, which is characterized.