DE2614065A1 - POWER TRANSISTOR COMPONENT - Google Patents

Description

Power transformer component

The invention relates to a semiconductor component, in particular in darlington transistor circuit, which is preferably is suitable for switching large currents on and off quickly.

A control connection 3 switch-off thyristor or a Darlington transistor circuits are known and commonly used used as a semiconductor switch that can switch a circuit on and off through which a large Current of more than a few amps depending on a small signal flows. Although the control terminal turn-off thyristor advantageously no power is required in order to maintain its conductive or non-conductive state, current pulses must opposite polarities are applied to its control connection (gate) in order to ignite it in each case or to delete. Therefore, an additional complicated control circuit must be used when the control terminal disconnection thyristor is used in a system that has a single source of direct current, such as e.g. B. an ignition circuit

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in a motor vehicle. In addition, throw a small current gain factor for power off and high Voltage drop in the forward direction due to the four-layer structure with the resulting loss of power serious problems with such a control terminal disconnect thyristor on. On the other hand, the Darlington transistor circuit requires a control power, to maintain their conductive state, and the DC gain factor must be increased to reduce the drive power. With a Darlington amplifier is the total DC gain multiplied by the product of the respective gain factors given to individual transistors, so that the gain can be made large as a whole. In this case however, the total gain in terms of the charge release time cannot be made arbitrarily large. Difficulties arise here in the construction of the circuit which cannot be reconciled with one another. If z. B. the charge accumulated between the base and emitter of a transistor must be released quickly a resistor with the lowest possible resistance value between the base and the emitter of the transistor are provided. On the other hand, if the current amplification factor of the transistor is to be made large, it must the resistor have a high resistance value, otherwise current through the short circuit with such a small one Resistance value between the base and the emitter scatters and the current amplification factor is reduced too much.

The Darlington transistor circuit difficulty discussed above is based on the arrangement of resistors in the current paths to release the basic charge carriers, and therefore this problem is solved when

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Semiconductor switching components, such as ζ. B. S cha It trans is tor en, used to release the base charge carriers. The invention is based on this basic concept. In addition, according to the invention, the Trans istor switch this can be produced at the same time as the Darlington transistor circuit is manufactured.

It is therefore an object of the invention to provide a power transistor circuit to be specified with high current amplification factor and fast breaking capacity.

The power transistor component according to the invention has

an N-conductive substrate,

an N ⁺ -type layer in a major surface of the N-type substrate,

a first and a second P-type layer in the other main surface of the N-conductive substrate,

a first and a second N-type layer in the the first or the second P-conductive layer,

means for electrically connecting the second P-type layer to the second N-type layer in the first P-type layer, and

third and fourth N-type layers in the first and second P-type layers, respectively.

In ei he _n development of the invention is a semiconductor device having a first and a second transistor in Darlington circuit is provided, wherein a first semiconductor switch is connected between the base and the emitter of the first transistor and a second semiconductor switch is connected between the base and the emitter of the second transistor

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The invention thus provides a power transistor component with a circuit of a first, a second, a third and a fourth transistor, wherein the first and second transistors are connected in Darlington, while the third and fourth transistors respectively between the base and the emitter of the first transistor and between the base and the emitter of the second transistor lie to the residual charges in the first and in the second transistor by enabling them by making them conductive depending on the input signals will.

The invention is explained in more detail below with reference to the drawing. Show it:

Fig. 1 is an electrical circuit diagram to explain the Mode of operation of the Darlington transistor according to the invention,

Fig. 2 is an electrical circuit diagram of the Darlington transistor circuit according to an embodiment of the invention,

3 shows the method steps for producing a conventional Darlington circuit,

4 shows the method steps for producing the inventive Darlington pair, and

5 A and B show characteristics of the conventional one and that of the invention A comparison of the Darlington pair.

In Fig. 1, which shows a circuit for explaining the principle of the invention, a load resistor 8 is between the Collector 2C of a transistor 2 and the positive electrode

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a direct current source 7, while a resistor 9 to Infeed of a bias current between the base IB of a transistor 1 and the positive terminal of the direct current source 7 is provided and the emitter 2E of the transistor 2 is connected to the negative terminal of the current source 7. The respective collectors IC and 2C of the transistors 1 and 2 are connected to each other, and the emitter IE des Transistor 1 is connected to base 2B of transistor 2. Switches 5 and 6 are between the base and emitter of transistor 1 and between the base and emitter of transistor 2.

If the switches 5 and 6 are opened in this structure, a conduction path is established between the emitter 2E and the collector 2C of the transistor 2 due to the base drive bias current flowing through the closed loop from the current source 7 via the resistor 9, the base IB of the transistor 1, the emitter IE of the transistor 1, the base 2B of the transistor 2, the emitter 2E of the transistor 2 and the current source 7 flows so that a load current flows through the closed loop from the current source 7 via the resistor 8, the collector 2C of the transistor 2, the emitter 2E of the transistor 2 and then to the power source J flows. In this mode of operation, the base drive bias current can be reduced to a value equal to the value of the desired load current divided by the product of the direct current amplification factors of the transistors 1 and 2.

If switches 5 and β are both closed,

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after the base current has just been interrupted in the transistor 1, the remaining charge carriers are in the respective Base layers IB and 2B of transistors 1 and 2 are released via switches 5 and 6 and disappear. The transistors 1 and 2 with their base connections short-circuited with their emitter connections are then turned off even in their steady state.

In this way, an effective reduction in DC gain due to bypassing Current through the used instead of the switches 5 and 6 in the conventional Darlington pair Resistances are prevented during the control operation, and the removal of the residual charges through the short circuits required time can be in the transient time the switched-off state can be shortened.

FIG. 2 shows an electrical circuit diagram of a Darlington circuit according to an embodiment of FIG Invention. Components that correspond to one another are provided with the same reference symbols in the figures. The excellent The feature of this circuit is the arrangement of two transistors 10 and 11 instead of switches 5 and 6 in the basic circuit of FIG. 1. The collector IOC of the transistor 10 is connected to the base IB of the transistor 1. The emitter 10E of the transistor 10 is connected to the base IE of the transistor 1. The collector HC des Transistor 11 is connected to base 2B of transistor 2. The emitter HE of the transistor 11 is connected to the Emitter 2E of transistor 2 connected. Resistors 12 and 13 are each connected to the base

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connections ICB and HB of transistors 10 and 11 and with their other terminals connected together.

With this arrangement, when a predetermined voltage is applied to the junction of the resistors 12 and 13 is, a current is delivered to the base HB of the transistor 11 via the resistor 13 to make the transistor 11 conductive close. Then the transistor 10 is due to the resistance 12, the base 10B and the emitter 10E of the The transistor 10 and the collector HC and the emitter HE of the transistor 11 are conductive. To this Way are the base and emitter of transistor 1 through transistor 10 and the base and emitter of the Transistor 2 short-circuited by transistor 11. If the lying at the junction of the resistors 12 and 13 Voltage is removed, the drive current through the transistors 10 and 11 is interrupted, and therefore the Short-circuit paths canceled. Accordingly, the circuit of FIG. 2 with the circuit of FIG. 1 with the switches open and 6 identical. In the circuit of Fig. 2, the switches, i.e. transistors 10 and H, can operate simultaneously Are opened and closed, so that the principle explained with reference to the figure is also achieved with the circuit of FIG will.

The arrangement of the circuit of Figure 2 with individual components makes the production expensive and the resulting circuit too complicated for free use.

3 and 4 show the process steps for producing composite solid-state circuits which

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are free from the disadvantages discussed above. 3 shows the process steps for producing a conventional one Pestkörper-Darlington pair, and Fig.4 shows the method steps for producing a composite solid-state transistor switching component according to the invention. The method steps (a), (b), (c) and (d) in the respective FIGS. 3 and 4 are the same and are therefore explained together.

In process step (a) in FIGS. 3 and 4, a N-type substrate 14 made of e.g. B. Si treated to serve as a carrier of the solid-state circuit to be manufactured.

In process step (b) in the 3 and 4, a N ⁺ type layer 15 in substrate 14 by doping with an N-type impurity by z. B. Diffusion formed.

In method step (c) in FIGS. 3 and 4, a P-conductive layer 16 is in the substrate 14 by doping a P-conductive contaminant by means of z. B. Diffusion formed.

In method step (d) of FIGS. 3 and 4, a trench 17, the bottom of which reaches the inside of the N-conductive layer 14, is made on the side of the P-conductive layer 16 in order to separate it into parts 16A and 16b. A SiO ₂ film 18 is then produced by means of surface oxidation. The SiOp-FiIm 18 serves not only as an electrical insulating layer, but also as a protective film.

The method steps (e), (f) and (g) in Fig. 3 and the method steps (e), (f) and (g) in Fig. 4 are in

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the same as the chemical treatment, but different from one another in their (geometric) pattern. First will be the production and operation of the conventional Darlington pair is explained in more detail with reference to FIG.

In process step (e) of Fig. 3, a part of the SiO ₂ film 18 by means of z. B. the photoresist method (photoresist method) or chemical etching removed, and N-conductive layers 19 and 20 are simultaneously formed by diffusion of an N-conductive impurity.

In method step (f) of Fig. 3, aluminum electrodes 21 to 25 are at predetermined locations by means Vacuum deposition made with a mask technique.

In method step (g) of FIG. 3, the electrodes 22 and 23 connected by a lead, and the electrodes 21, 24 and 25 each come with an emitter terminal 28, a base connection 29 and a collector connection 30. Using vacuum deposition with a Masking technique, a resistive layer 26 between the electrodes 21 and 22 and a resistive layer 27 are also used formed between the electrodes 23 and 24.

Two NPNN ⁺ transistors are thus connected in a longitudinal arrangement, separated by the trench 17, in a Darlington circuit. The transistors share the N ⁺ layer as their collector area. The part to the right of the trench 17 in the drawing corresponds to the transistor 1 in FIG. 1 and the part to the left of the trench 17 in the drawing corresponds to the transistor in FIG. 1. The N-conducting layer 20 and the P-conducting layer

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Layer 16A. each serve as an emitter IE and as a base IB. The N-type layer 19 and the P-type layer 16b each serve as an emitter 2E and a base 2B. As explained above, the emitter is IE and the base is 2B connected to each other by a line. In this way the transistors form a Darlington pair. The resistance layers 27 and 28 are provided between the base terminals and the emitters of the transistors, respectively and serve instead of the switches 5 and 6 of FIG. 1 to release the residual charges.

If a voltage is properly applied between the base terminal of one transistor and the emitter terminal 28 of the other transistor, minority charge carriers (i.e. electrons in this case) are injected into the base layers I6A and 16b of the transistors, so that the amplified currents to the emitters I9 and 20 Flow via the base-collector PNN ⁺ transitions (I6A - 14 - 15, 16b - 14 - 15), which are biased in the reverse direction. In this way, an operation similar to that of an ordinary transistor can be achieved.

The following are the manufacture and operation of a Semiconductor component according to the invention described in more detail.

In method step (e) of FIG. 4, N-conductive layers 19, 20, 31 and 32 are formed simultaneously by means of diffusion formed by N-conductive impurities.

In process step (f) of Figure 4, four parts of the SiOg film removed to electrodes 22, 24, 34 and 36

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the P-type layers 16A and 16b. In addition, electrodes 21, 23, 33, 35 and 25 are formed on the N-type layers 19, 20, 31 and 32 and the N ⁺ -type layer 15, respectively.

In method step (g) of FIG. 4, the electrodes 33, 22 and 23 are connected to one another by a line, and the electrodes 35 and 24 are connected to each other by another lead wire. The electrodes 21, 24, 34, 36 and 25 are each provided with an emitter connection 28, a base connection 29, a second base connection 37 * a third base terminal 38 and a collector terminal 30 are provided.

In this arrangement, in addition to the two four-layer NPNN ⁺ transistors (20 - I6A - 14 - I5, 19 - 16b - 14 - 15), corresponding to transistors 1 and 2 in FIG -conductive layer I6A and the electrode 36 on the P-conductive layer I6A between the N-conductive layers 20 and 32 lateral transistors together with the N-conductive layer 20, and the N-conductive layer 31 and the electrode 34 form another lateral Transistor together with the N-conductive layer 19.

In particular, the lateral transistor from the layers 32 - 16A - 20 and the one corresponding to the transistor 1 share Transistor the emitter region 20, this lateral transistor being the transistor 10 in FIG. The lateral The transistor from layers 31 - 16b - 19 and the transistor corresponding to transistor 2 share the emitter

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area I9, this lateral transistor being the transistor in Fig. 2 is. The N-type layers 32 and 3I are the collectors of the transistors 10 and 11, respectively. The N-conductive layer 32 is connected to the base of the transistor 1 connected while the N-type layer 3I and the base of the transistor 2 are connected to one another. The arrangement thus formed is illustrated by the circuit in FIG. The electrodes 36 and 34 correspond to, respectively Connections IOB and HB in Fig. 2 and are with the second and third base terminal 37 and 38 are provided. In the process step (g) of Figure 4, terminals 37 and 38 are shown as external terminals; however, there are others too Embodiments possible. A resistive film can e.g. B. by means of vacuum evaporation on part of the SiOp film may be provided, this film connecting terminal 37 to terminal 38 and an external terminal in the middle of the resistance film is provided. In this case it can the entire circuit of FIG. 2 according to the method for manufacturing a conventional Darlington circuit as a whole getting produced.

FIGS. 5A and 5B show characteristic curves in comparison of the semiconductor components which are shown in the respective last process steps (e) of FIGS. 3 and 4, FIG. 5A being the changing with the collector current Shows the DC gain factor and FIG. 5B shows the charge release time, which varies with the base current, for a Represents switching operation with high collector current (6A).

As follows from Figures 5A and 5B, the DC gain is of the component according to the invention compared to the gain factor of the conventional component greatly improved, with the charge release time that the

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Switching speed strongly influenced in the invention is much shorter than the conventional component. In addition, since the component according to the invention has a large DC gain factor, a certain collector current can flow in and out through a smaller base current be switched off than this is required in the conventional component to the same collector current to control. This means that the charge release time can be further reduced.

In the embodiment of the invention explained above become the respective paths between the base terminals and the emitters of the first and the second transistor switched on and off simultaneously by bipolar transistors; however, the bipolar transistors can through Field effect transistors are replaced, which have the advantage of a large input impedance.

In the case of the invention, the residual charge carriers disappear fast in the base regions because the base-emitter biases of the Darlington transistors are fast can be switched positively, and a high current gain factor can be achieved, since the base-emitter bypasses are interrupted during the conducting period.

The inventive Trans istor switch with the desired Characteristic curves can be used without any new manufacturing step and can be manufactured without additional effort, since its manufacturing process is compared to the conventional Transistor requires no additional steps.

As can be seen from the embodiment of Figures 2 and 4, NPN transistors are used as switches for removal

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of the charges accumulated in the Darlington pair. It is z. B. a high speed switch with a darlington pair used to make the primary current to control the ignition system of a motor vehicle. The power source of an automobile is usually one Unidirectional power source with negative terminal grounded. The circuit in which the base connections and the Emitter of the first and the second transistor in Darlington connection short-circuited by NPN transistors is very easy to control because the NPN transistors are operated when a positive voltage is applied to the Base connections.

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Claims (5)

26H065 - 15 claims Γ 1. Power transistor component, with an N-conductive substrate, an N ⁺ -conductive layer in a major surface of the N -conductive substrate, a first and a second P-type layer in the other main surface of the N-conductive substrate, first and second N-type layers in the first and second P-type layers, respectively, and means for electrically connecting the second P-type layer to the second N-type layer in FIG the first P-type layer, not counted individually a third and a fourth N-conductive layer (32 and 31, respectively) in the first and the second P-conductive layer (16A or 16b) (Fig. 4g). 2. Power transistor component according to claim 1, characterized in that the fourth N-conductive layer (31) is connected to an electrode (23) on the second P-conductive layer (16b) by an external conductor (Pig.4g). 3. Le is ungs trans is or-Baue learn nt according to claim 2, thereby characterized in that a second and a third electrode (35, 24) on the third N-type layer (32) and the first P-type layer (16A.) Are provided and connected to each other by an external connecting member (Fig. 4g). 609842/0732 26H065 - ιό - 4. Semiconductor component with a first and a second Transistor in Darlington circuit, characterized in that a first semiconductor switch (10) between the base (IB) and the emitter (IE) of the first transistor (1) and a second semiconductor switch (11) between the base (2B) and the emitter (2E) of the second transistor (2) are (Fig. 2). 5. Semiconductor component according to claim 4, characterized in that that the first and the second semiconductor switch (10, 11) are NPN transistors. 609842/073? Blank page