Patent Publication Number: US-2022216298-A1

Title: Method and device for using a semiconductor component

Description:
FIELD 
     The present invention relates to a method and a device for using a semiconductor component. 
     BACKGROUND INFORMATION 
     Such a semiconductor component may contain a dielectric layer including defects. In the intended operation of the semiconductor component, the defects may migrate in the dielectric layer between electrodes of the semiconductor component. The defects may accumulate at one of the electrodes. A dielectric breakthrough may thus occur at this electrode, which shortens the service life of the semiconductor component. 
     After a dielectric breakthrough, a function of the semiconductor component may be reestablished under certain conditions. This is described, for example, in J. Wang, C. Salm, E. Houwman, M. Nguyen and J. Schmitz, “Humidity and polarity influence on MIM PZT capacitor degradation and breakdown,” 2016 IEEE International Integrated Reliability Workshop (IIRW), South Lake Tahoe, C A, 2016, pp. 65-68, doi: 10.1109/IIRW.2016.7904903. 
     SUMMARY 
     A method and a device in accordance with the present invention may enable a use of this property to extend the lifetime of the semiconductor component. 
     In accordance with an example embodiment of the present invention, the method for using a semiconductor component in which a dielectric layer is situated between a first electrode and a second electrode of the semiconductor component, defects of a first defect type being present in the dielectric layer, includes the steps of operating the semiconductor component using a first voltage having a first polarity between the first electrode and the second electrode, determining whether or not a condition is met for switching over from operating the semiconductor component using the first voltage to operating the semiconductor component using a second voltage, which has a second polarity opposite to the first polarity, continuing the operation of the semiconductor component using the first voltage if the condition is not met, and otherwise ending the operation of the semiconductor component using the first voltage, and operating the semiconductor component using the second voltage between the first electrode and the second electrode. In the intended operation of the semiconductor component using the first voltage, a reversion process is thus reliably started before a dielectric breakthrough shortening the lifetime of the semiconductor component occurs. 
     In accordance with an example embodiment of the present invention, the method preferably includes the steps of determining whether or not a condition is met for switching over from operating the semiconductor component using the second voltage to operating the semiconductor component using the first voltage, continuing the operation of the semiconductor component using the second voltage if the condition is not met, and otherwise ending the operation of the semiconductor component using the second voltage, and operating the semiconductor component using the first voltage between the first electrode and the second electrode. This enables a continuous operation of the semiconductor component using the intended first voltage and including interposed reversion process. 
     In accordance with an example embodiment of the present invention, a duration of the operation of the semiconductor component using the second voltage is preferably determined, the condition for switching over from operating the semiconductor component using the second voltage to operating the semiconductor component using the first voltage is met if the duration exceeds a limiting value, which is defined by a time period in which the second voltage causes a movement of defects of the first defect type in a predefined position in the dielectric layer in the direction toward the second electrode. 
     In accordance with an example embodiment of the present invention, a leakage current is preferably determined during the operation of the semiconductor component using the second voltage, the condition for switching over from operating the semiconductor component using the second voltage to operating the semiconductor component using the first voltage being met if the leakage current exceeds or falls below a threshold. 
     In accordance with an example embodiment of the present invention, a duration of the operation of the semiconductor component using the first voltage is preferably determined, the condition for switching over from operating the semiconductor component using the first voltage to operating the semiconductor component using the second voltage being met when the duration exceeds a limiting value. 
     A leakage current which flows in the operation of the semiconductor component using the first voltage is preferably determined, the condition for switching over from operating the semiconductor component using the first voltage to operating the semiconductor component using the second voltage being met when the leakage current exceeds a threshold. 
     The semiconductor component is preferably heated during the operation of the semiconductor component using the second voltage. 
     The semiconductor component is preferably heated during the operation of the semiconductor component using the second voltage to a temperature which is higher than a temperature of the semiconductor component during the operation of the semiconductor component using the first voltage. 
     The semiconductor component is preferably heated during the operation of the semiconductor component using the second voltage to a temperature in a range of 100° C. to 250° C., preferably to a temperature of 150° C. or 200° C. A higher voltage or temperature causes a shorter time of the reversion process. The shortening of the duration is not linearly related to the increase of the temperature or the increase of the second voltage. An excessively high second voltage or temperature may cause destruction of the second electrode, for example, due to accumulation there. The accumulation reduces the Schottky barrier and a dielectric breakthrough may occur. In the case of a lower voltage in relation thereto, at equal temperature, the threshold value of the defect density which results in the breakthrough is higher. This means the temperature may be selected to be higher with decreasing second voltage, without a dielectric breakthrough occurring. The temperature is a good parameter to set the speed of the movement of the defects. 
     In accordance with an example embodiment of the present invention, in operation using the first voltage, the semiconductor component preferably drives an actuator, in particular a MEMS, a micromirror, a print head, or a loudspeaker, the actuator not being driven by the semiconductor component in operation using the second voltage, in particular in an idle state of a device. 
     The semiconductor component may be operated using a second voltage higher than the first voltage. 
     In accordance with an example embodiment of the present invention, the device includes the semiconductor component, which includes a dielectric layer between a first electrode and a second electrode of the semiconductor component, defects of a first defect type being present in the dielectric layer, and a regulating and/or control unit which is designed to carry out steps in the method. 
     The dielectric layer may include defects of at least one further defect type which are movable in the direction toward the second electrode upon application of the first voltage. 
     Further advantageous specific embodiments result from the following description and the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a schematic representation of a first embodiment of a semiconductor component, in accordance with the present invention. 
         FIG. 2  shows a schematic representation of a second embodiment of a semiconductor component, in accordance with the present invention. 
         FIG. 3  shows a schematic representation of a device for activating the semiconductor component, in accordance with the present invention. 
         FIG. 4  shows steps in a method for use of a semiconductor component, in accordance with the present invention. 
         FIG. 5  shows a first density p of a distribution of defects in the semiconductor component, in accordance with the present invention. 
         FIGS. 6A through 6D  show current curves. 
         FIG. 7  shows a second density p of the distribution of defects in the semiconductor component, in accordance with the present invention. 
         FIG. 8  shows a third density p of the distribution of defects in the semiconductor component, in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
       FIG. 1  shows a schematic representation of a semiconductor component  100  according to a first embodiment. Semiconductor component  100  includes a first electrode  102 , a second electrode  104 , and a dielectric layer  106 . 
     Dielectric layer  106  is situated between first electrode  102  and second electrode  104 . In the example, first electrode  102  and second electrode  104  are situated on mutually opposing sides of dielectric layer  106 . 
     Defects D 1  of a first defect type are present in the dielectric layer. These defects D 1  are situated in a first starting position in the example. The first starting position is defined in the example by a manufacturing process of dielectric layer  106 . Defects D 1  are in particular situated closer to second electrode  104  than to first electrode  102 . 
       FIG. 2  shows a schematic representation of semiconductor component  100  according to a second embodiment. Semiconductor component  100  according to the second embodiment is designed like semiconductor component  100  according to the first embodiment. In contrast to the first embodiment, in the second embodiment, defects of a second defect type are additionally present in the dielectric layer. These defects D 2  are situated in a second starting position in the example. The second starting position is defined in the example by a manufacturing process of dielectric layer  106 . 
     Defects D 2  are situated in the example at a different position than defects D 1 . Defects D 2  are in particular situated closer to first electrode  102  than to second electrode  104 . 
     Defects D 1  of the first defect type and defects D 2  of the second defect type are charged defects which move in the event of an applied potential between first electrode  102  and second electrode  104  in accordance with their charge to a particular interface between dielectric layer  106  and either first electrode  102  or second electrode  104 . The interface is referred to hereinafter as the “interface.” This transport of the charged defects is determined by defect properties and a “hopping mechanism.” 
     Hopping mechanism in this context means that a displacement, i.e., a hopping, of the defects takes place in an electrical field E caused by particular applied voltage U in dielectric layer  106  of thickness d. The defects of a defect type i move along localized defect states having a mean effective distance al. This results in a speed vi of the movement of the defects of defect type i. Speed vi is described via the conventional approach of variable range hopping: 
     
       
         
           
             
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     In this case, C 0,i (a i ) represents a function which represents an influence of a local defect distribution on a characteristic speed v i  of defects i in dielectric layer  106 . This defect distribution represents a property of dielectric layer  106 . This property partially determines the movement of the defects of defect type i in dielectric layer  106 . The parameters decay length α, mean effective distance a i , activation energy E A,0,i , and electric charge N q,i  of the defects of defect type i are physical properties. The Boltzmann constant is denoted by k B . The temperature of the surroundings of the observed defect, in particular the temperature in dielectric layer  106 , is denoted by T. 
     Up to a dielectric failure, a time curve of a leakage current density J TED  may be determined via the equation of the thermionic emission diffusion theory according to Crowell and Sze: 
     
       
         
           
             
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     In this case, q represents the unit charge, N C  the effective state density in the power band, v R  the effective recombination speed, v D  the effective diffusion speed, Φ B   eff    
     the effective Schottky barrier, kB the Boltzmann constant, T the temperature of the surroundings, and U the voltage over dielectric layer  106 . 
     Defects i having positive charge migrate to the electrode having negative potential and accumulate in its vicinity in the dielectric layer. Defects i having negative charge move to the electrode having positive potential and accumulate at the interface. Effective Schottky barrier Φ B   eff  thus changes. 
     A barrier height change ΔΦ i , which is generated by defects i, is characterized by its maximum height δΦ i  and a characteristic time constant τ i . Characteristic time constant τ i  defines a duration in which barrier height change ΔΦ i  changes most strongly over time t: 
     
       
         
           
             
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     Maximum height δΦ i  is a function of a number Z i  of defects i and is dependent on the type of the interface. The term 
     
       
         
           
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     describes a static distribution of defects i in the material, in particular around the particular starting position. The starting position represents a focal point of the distribution in the example. 
     Time constant τ i  may be different for the movement under the influence of a first voltage U 1  than for the movement under the influence of a second voltage U 2 . Time constant τ i  may be defined by a mobility of defects i under an influence of electrical field E in dielectric layer  106  and the path to be covered to reach the particular interface in dielectric layer  106 . During the displacement in the interior of dielectric layer  106 , defect type i has to cover a distance dl of the focal point of its distribution to the interface. Together with speed vi, characteristic time constant τ i  results for the accumulation process of defects i in 
     
       
         
           
             
               τ 
               i 
             
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     Time constant τ i  is determinable from a measurement of the leakage current over time, an evaluation of the time-dependent curve with the aid of the equations of the thermionic emission diffusion theory according to Crowell and Sze, and the time-dependent behavior of the barrier height change. Activation energy E A,0,i  and electrical charge N q,i  of the defects of defect type i may be determined with the aid of multiple measurements of τ i  at different temperatures T and voltages U. 
     During the operation of semiconductor component  100  according to the first embodiment with application of first electrical voltage U 1  having a first polarity, an electrical load results. 
     Under the electrical load, charged defects D 1  of the first defect type may reach the interface. Charged defects D 1  of the first defect type which reach the interface accumulate at the interface. The accumulation of charged defects at the interface at first electrode  102  during the electrical load using first electrical voltage U 1  is a reversible process, in the meaning that by applying second electrical voltage U 2  having a polarity opposite to the polarity of first electrical voltage U 1 , these charged defects D 1  of the first defect type move in the opposite direction and thus move away from the interface again. 
     For the operation of semiconductor component  100  according to the second embodiment, the same applies to defects D 1  of the first defect type. Charged defects D 2  of the second defect type may moreover be movable by first electrical voltage U 1  in the same direction as defects D 1  of the first defect type or in the direction opposite thereto. An accumulation of defects D 2  of the second defect type at the interface, which these defects seek upon application of the first electrical voltage, is also reversible in the example by applying second electrical voltage U 2 . 
     The first embodiment and the second embodiment of semiconductor component  100  are examples. Semiconductor component  100  may include more than two electrodes. Semiconductor component  100  may include more than one dielectric layer lying between each two electrodes. 
     In such semiconductor components, a dielectric breakthrough is possible when they are operated under application of an electrical voltage. When a dielectric breakthrough occurs, the interface is partially or completely destroyed. When a dielectric breakthrough occurs, a service life of semiconductor component  100  is shortened. The dielectric breakthrough occurs, for example, when a number of charged defects which accumulate at the interface exceeds a voltage-dependent threshold value. 
     Physical properties and manufacturing-specific influences on these physical properties may be influenced by an optimization of process conditions and/or a process control during manufacturing of dielectric layer  106 . The service life may thus be lengthened. 
     A growth, growth conditions, or a material composition is influenced, for example, by the process conditions and/or the process control. An intentional or unintentional doping and/or contamination during the growth process or in following processes results, for example, due to the process conditions and/or the process control. 
     The service life of semiconductor component  100  is lengthened, as described hereinafter, by a change of the electrical operating conditions during operation. 
     This is achieved by a utilization of reversible degradation processes in dielectric layer  106  and a reversal of the electrical load direction during the active service life of semiconductor component  100 . 
     This behavior of the charged defects is utilized in the example by an intended operation of semiconductor component  100  and by a targeted load outside the intended operation against the polarity selected in intended operation. 
     Therefore, for example 
     a) The accumulation of defects or of defects of a specific defect type is entirely prevented. 
     b) The accumulation of defects or of defects of a specific defect type is only permitted up to a determinable degree, in the example a number of defects at the interface which is less than the threshold value. 
     c) The accumulation of defects or of defects of a specific defect type at the interface is reversed entirely or to a determinable degree. 
     An accumulation of defects at the interface is always linked to an influence on the interface and thus determines a leakage current level. 
     One goal of the method described hereinafter may be to prevent a dielectric breakthrough in that an accumulation greater than a critical defect density is prevented. 
     One goal of the method described hereinafter may be to ensure a maximum leakage current level in which an accumulation greater than a defect density corresponding to the maximum leakage current level is prevented. 
     An effectiveness of the method described hereinafter may be influenced and optimized by a selection of second voltage U 2  for a targeted load of semiconductor component  100  or by a selection of a temperature at which the targeted load is applied. 
     A higher or lower temperature may be set, for example, via a heating or cooling element. An optimization exists, for example, if, due to the temperature or selected second voltage U 2 , the movement speed of the participating defects is such that the reversal of the accumulation takes place significantly faster than the accumulation, which is disadvantageous in particular, under operating conditions for the intended operation of semiconductor component  100 . 
     The method is optimizable by targeted management of the operation of semiconductor component  100 . A point in time for the application of second voltage U 2  may be systematically selected, for example. The point in time is determined, for example, for a device which includes semiconductor component  100  and an accumulator for applying first voltage U 1  in intended operation, in such a way that the point in time is during a charge cycle of the accumulator. An undesired energy consumption from the accumulator is thus prevented. The point in time may also be at intervals definable by the user of the device. The point in time defines, for example, a start of a time period in which second voltage U 2  is applied. Time periods may thus be prevented in which the device is inadvertently not available for the intended operation. The point in time may be established, in particular at intervals, on the basis of an operating duration of the device and/or a load profile of the semiconductor component or the accumulator or the device. 
     The point in time may be when the duration of the operation using the first voltage reaches time constant t 1 . The point in time may be before reaching time constant t 1 . The point in time may be determined as a function of time constant t 1 . For example, point in time z is determined as 
     
       
      
       z=t 
       1 
       −s  
      
     
     s being a safety deduction, for example in an order of magnitude of 103 seconds. 
     The point in time may be adapted to the actual behavior of semiconductor component  100  by monitoring the leakage current. 
     The point in time, an interval, and/or a current level from which the operation is to take place using second voltage U 2  is determined, for example, as a function of a deterministic curve of a leakage current degradation and in dependence on knowledge about the leakage current mechanism and the load profile. 
     A further implementation could be ensured by operation using first voltage U 1  and second voltage U 2  under time-controlled or event-controlled change of the operating polarity in particular. 
     For a preferred implementation of the method, the point in time or the duration is determined such that no dielectric breakthrough or high leakage current level is induced due to accumulation at the opposite interface by the operation using second voltage U 2 . 
       FIG. 3  shows a device  300  for activating semiconductor component  100 . Semiconductor component  100  is designed in the example to drive an actuator. The actuator is in particular a MEMS, a micromirror, a print head, or a loudspeaker. The actuator is in particular not driven by semiconductor component  100  in an idle state of the device in operation using second voltage U 2 . 
     Device  300  includes a regulating and/or control unit  302 , which is designed to carry out steps in a method described hereinafter for activating semiconductor component  100 . Device  300  is at least temporarily connectable via a first conductor  304  to first electrode  102  of semiconductor component  100 . Device  300  is at least temporarily connectable via a second conductor  306  to second electrode  104  of semiconductor component  300 . 
     Regulating and/or control unit  302  is designed in the example to output first voltage U 1  having the first polarity. First voltage U 1  is applied in the example between first electrode  102  and second electrode  104  when they are connected using the particular conductor to a device  300  and regulating and/or control unit  302  outputs first voltage U 1 . 
     Regulating and/or control unit  302  is designed in the example to output second voltage U 2  having the second polarity. The second polarity is opposite the first polarity in the example. Second voltage U 2  is applied in the example between first electrode  102  and second electrode  104  when they are connected using the particular conductor to device  300  and regulating and/or control unit  302  outputs second voltage U 2 . 
     The control unit may be designed to output a unipolar alternating current signal for first voltage U 1 . A DC voltage component of first voltage U 1  is, for example, in a range of 5 V to 80 V and is preferably 5 V, 10 V, or 20 V or 80 V. The AC voltage component of first voltage U 1  may be less than or equal to the DC voltage component in absolute value, for example. The AC voltage component is preferably 5 V+/−3 V or 10 V+/−5 V or 20 V+/−15 V or 80 V+/−60 V. 
     The control unit may be designed to output an essentially constant value for second voltage U 2 . Second voltage U 2  is greater in the example, for example, 15 V greater, than first voltage U 1  in intended operation. This value is, for example, in a range of 1 V to 150 V and is preferably 2 V or −5 V or 10 V or 20 V or 40 V or 80 V or 100 V. 
     For continuous operation the control unit may be designed instead to output a unipolar alternating current signal for second voltage U 2 . The unipolar alternating current signal for second voltage U 2  is, for example, the unipolar alternating current signal for first voltage U 1  having opposite polarity. 
     Dielectric layer  106  is preferably formed as a polycrystalline oxidative high-k dielectric material. 
     Dielectric layer  106  is in particular formed as a PZT layer. PZT denotes Pb(Zr x Ti 1-x )O 3  in this case. 
     Dielectric layer  106  is formed in particular as a KNN layer. KNN denotes (K x  Na 1-x )NbO 3  in this case. 
     Dielectric layer  106  may be formed in particular as a HfO 2 , HfZrO 2 , ZrO 2 , BaTiO 3 , SrTiO 3 , or (Ba x Sr 1-x )TiO 3  layer. 
     Dielectric layer  106  is preferably doped. Dielectric layer  106  is, for example, a PZT layer, which is doped using nickel: 
       Pb(Zr x Ti 1-x )O 3 Ni y . 
     Both the PZT layer and also the KNN layer may have dopants other than nickel, for example, Nb, La, Mn, Mg. 
     Dielectric layer  106  is preferably formed as a sputtered PZT layer. The so-called target material is deposited in a plasma on a substrate for this purpose. PZT is used as the target material, for example. The sputtered PZT layer preferably has a deposition temperature of less than 500° C. in this context. 
     The thickness of dielectric layer  106  is preferably in the range 500 nm to 4 μm. This is a reasonable range for actuators. The layer thickness is preferably 1 μm or 4 μm. Greater layer thicknesses are also possible. The described process may be carried out for all layer thicknesses. 
     Lower layer thicknesses are also possible. The thickness of the dielectric layer is preferably in the range less than 500 nm, for example, for applications outside of actuators. One example of this is an application of high-k dielectric materials, for example, as a memory. The memory may be a resistive Random Access Memory, ReRAM, or a ferroelectric Random Access Memory, FeRAM. For these other applications, thicknesses of 15 nm-200 nm are reasonable depending on the application. 
     In addition, very thin high-k dielectric materials including layers are usable, for example, as gate oxides in very many applications. HfO 2  or SiO 2  having a layer thickness less than or equal to 50 nm may be provided, for example, as dielectric layer  106 . 
     The regulating unit may be designed to regulate a setpoint value for first voltage U 1 . This setpoint value is, for example, in a range of 1 V to 20 V. 
     The regulating unit may be designed to regulate a setpoint value for second voltage U 2 . This setpoint value is, for example, in a range of −1 V to −20 V. 
     In this case, a voltage measuring unit may be provided, which is designed to detect the voltage between first electrode  102  and second electrode  104 . The regulating unit is designed in this case to reduce a regulating deviation, which is determined as a function of a difference of this detected voltage from the setpoint value. 
     Device  300  optionally includes a heating unit  308  in the example. Heating unit  308  is designed in the example to heat dielectric layer  106 . Heating unit  308  may be designed as a heating coil. Heating unit  308  is situated in the example on dielectric layer  106 . Heating unit  308  is situated electrically and/or electromagnetically insulated from dielectric layer  106  in the example. A corresponding arrangement on a side of one of the electrodes facing away from dielectric layer  106  is also possible. 
     Heating unit  308  may also be situated externally on a housing around semiconductor element  100 . Dielectric layer  106  and first electrode  102  and second electrode  104  may be situated in the housing. 
     In the example, heating unit  308  is electrically heatable via a first contact  310  and a second contact  312 . 
     Regulating and/or control unit  302  is at least temporarily connectable, for example, via a third conductor  314  to first contact  310  and via a fourth conductor  316  to second contact  312 , in order to effect a current I 1  through heating unit  308 . 
     Regulating and/or control unit  302  is designed in the example to output current I 1 . 
     Device  300  optionally includes a voltage source or current source  318  in this example. Voltage or current source  318  may also be situated outside the device. A processing unit  320 , in particular a microprocessor, which is designed to activate semiconductor component  100 , is provided in regulating and/or control unit  302  in the example. 
     The control unit may be designed to output an essentially constant value for current I 1 . This value is, for example, in a range by which heating unit  308  heats the dielectric layer to a temperature between 100° C. and 200° C. 
     The regulating unit may be designed to regulate a setpoint value for current I 1 . This setpoint value is, for example, in a range by which heating unit  308  heats the dielectric layer to a temperature between 100° C. and 200° C. In this case, a temperature measuring unit may be provided which is designed to detect the temperature of dielectric layer  106 . The regulating unit is designed in this case to reduce a regulating deviation, which is determined as a function of a difference of this detected temperature from the setpoint value. The temperature may also be detected at another point, for example, on the housing, of heating unit  210  or in the surroundings of dielectric layer  106 . Device  300  optionally includes a current measuring unit, which is designed to detect a current that flows through first electrode  102  or second electrode  104 . It may be provided that the current measuring unit detects the current that flows through first conductor  304 . It may be provided that the current measuring unit detects the current that flows through second conductor  306 . 
     Regulating and/or control unit  302  is designed to output either first voltage U 1  or second voltage U 2 . 
     Regulating and/or control unit  302  may optionally be designed to output either first voltage U 1  or second voltage U 2  as a function of the detected current. 
     A method for using semiconductor component  100  is described hereinafter on the basis of  FIG. 4 . In the example, semiconductor element  100  is activated by device  300 . 
     In a step  402 , semiconductor component  100  is operated using first voltage U 1  having the first polarity between first electrode  102  and second electrode  104 . 
     In  FIG. 5 , a density p of a distribution  500  of defects D 1  of the first defect type is schematically shown over a curve x of dielectric layer  106  in starting position  502 , i.e., the focal point of distribution  500  at the beginning of the application of first voltage U 1  in the intended operation of semiconductor component  100 . Density p of defects D 1  of the first defect type is greatest in starting position  502  and decreases strongly with increasing distance from starting position  502 . At a location  508  of first electrode  102  and a location  506  of second electrode  104 , density p goes to zero in the example. Defects D 1  of the first defect type move, while first voltage U 1  is applied, in direction  504  away from location  506  of second electrode  104  toward location  508  of first electrode  102 . Until reaching location  508  of first electrode  102 , most defects D 1  of the first defect type have to cover a distance  510  between starting position  502  and location  508  of first electrode  102 . A duration until most defects D 1  of the first defect type have covered distance  510  is determinable as a function of a speed at which defects D 1  of the first defect type move in dielectric layer  106 . 
     In a step  404 , it is determined whether a condition for switching over from the operation using first voltage U 1  to operation using second voltage U 2  is met. In one aspect, the condition is met when a duration of the operation of semiconductor component  100  using first voltage U 1  exceeds a first limiting value. In one aspect, the condition is met when a leakage current, which flows in operation of semiconductor component  100  using first voltage U 1  through first electrode  102 , second electrode  104 , or first conductor  302  or second conductor  304 , exceeds a threshold. 
       FIG. 6A  shows a current curve  600   a  over time t. Current curve  600   a  is to be expected at a temperature of 200° C. and first voltage U 1  of −5 V between first electrode  102  and second electrode  104  when the dielectric breakthrough is avoided. 
       FIG. 6B  shows a current curve  600   b  over time t. Current curve  600   b  is to be expected at a temperature of 200° C. and first voltage U 1  of −5 V between first electrode  102  and second electrode  104  when the dielectric breakthrough is not avoided. 
     The first limiting value is defined by a first time period in which first voltage U 1  causes a movement of defects of the first defect type from a first position in dielectric layer  106  up to a second position in dielectric layer  106  in the direction toward first electrode  102 . 
     The first limiting value is selected to be shorter in one aspect than the duration until most defects D 1  of the first defect type have covered distance  510 , in order to reduce a number of defects D 1  of the first defect type which accumulate at the interface at first electrode  102 . 
     A time of 1*10 4  seconds is selected for the first limiting value, for example. 
     If the condition is met, a step  406  is carried out. Otherwise, step  402  is carried out. 
     In step  406 , the operation of semiconductor component  100  using first voltage U 1  is ended. 
     A step  408  is then carried out. 
     In step  408 , semiconductor component  100  is operated using second voltage U 2  between first electrode  102  and second electrode  104 . 
     A reversion process is thus initiated. 
       FIG. 7  schematically shows density p of distribution  500  of defects D 1  of the first defect type over curve x of dielectric layer  106  at the beginning of the application of second voltage U 2 . Density p of defects D 1  of the first defect type is greatest in a position  702 , i.e., the focal point of distribution  500 , and decreases strongly with increasing distance from position  702 . At location  508  of first electrode  102 , density p increases strongly in the example. Defects D 1  of the first defect type accumulated in operation of semiconductor component  100  using first voltage U 1  are accumulated there. At location  506  of second electrode  104 , density p goes to zero in the example. 
     Defects D 1  of the first defect type move while second voltage U 2  is applied in direction  704  away from location  508  of first electrode  102  toward location  506  of second electrode  104 . Until reaching location  506  of second electrode  104 , most defects D 1  of the first defect type have to cover a distance  706  between position  702  and location  506  of second electrode  104 . A duration until most defects D 1  of the first defect type have covered this distance  706  is determinable as a function of a speed at which defects D 1  of the first defect type move in dielectric layer  106 . This speed is settable as a function of a temperature and second voltage U 2 . In the example, the temperature is maintained unchanged. 
     A step  410  is then carried out. 
     In step  410  it is determined whether or not a condition for switching over from operating semiconductor component  100  using the second voltage to operating semiconductor component  100  using the first voltage is met. 
     The condition for switching over from operating semiconductor component  100  using second voltage U 2  to operating semiconductor component  100  using the first voltage is met if the leakage current falls below or exceeds a threshold depending on the case. In many applications, the leakage current falls below the threshold when switching is to take place. However, a precisely opposite variant is also possible. 
       FIG. 6C  shows a current curve  600   c  in the reversion process over time t. Current curve  600   c  is to be expected at a temperature of 200° C. and second voltage U 2  of +20 V between first electrode  102  and second electrode  104  when the dielectric breakthrough is avoided. 
       FIG. 6D  shows a current curve  600   d  over time t. Current curve  600   d  is to be expected at a temperature of 200° C. and second voltage U 2  of +20 V between first electrode  102  and second electrode  104  when the dielectric breakthrough is not avoided. For example, a duration of the operation of semiconductor component  100  using second voltage U 2  is determined. The condition is met, for example, if the duration exceeds a second limiting value. The second limiting value is determined in the example as a function of second voltage U 2  in such a way that most defects D 1  of the first defect type do not overcome distance  706 . The temperature at semiconductor component  100  or dielectric layer  106  may also be taken into consideration in order to determine the second limiting value. In the example, the second limiting value of 103 seconds is selected. 
     The second limiting value is defined in the example by a second time period, in which second voltage U 2  causes a movement of most defects D 1  of the first defect type from position  702  into starting position  502 . An original density p of distribution  500  of defects D 1  of the first defect type is reestablished by this complete reversion process. 
     The second limiting value may also be defined by a second time period, in which second voltage U 2  causes a movement of most defects D 1  of the first defect type from position  702  into another position  802  in the dielectric layer in the direction toward second electrode  106 . The focal point of distribution  500  is at other position  802  in this case. 
     Other position  802  is closer in the example to position  702  than starting position  502 . The reversion process is thus not carried out up to original starting position  502 . The duration of the reversion process is thus shortened. 
       FIG. 8  schematically shows density p of distribution  500  of defects D 1  of the first defect type over curve x of dielectric layer  106  for this case. Density p of defects D 1  of the first defect type is greatest in position  802  and decreases strongly with increasing distance from position  802 . At location  508  of first electrode  102 , density p increases in the example. Defects D 1  of the first defect type accumulated in operation of semiconductor component  100  using first voltage U 1  are accumulated there, which have not yet been removed from the interface by the operation using second voltage U 2 . The number of defects D 1  of the first defect type which are still accumulated in the interface is reduced in relation to the number which were accumulated at the beginning of the operation using second voltage U 2 . At location  506  of second electrode  104 , density p goes to zero in the example. Defects D 1  of the first defect type move while second voltage U 2  is applied in direction  806  away from location  508  of first electrode  102  toward location  506  of second electrode  104  until most defects D 1  of the first defect type have reached a distance  804  from location  508  of first electrode  102 . 
     In another aspect, a leakage current which flows in operation of semiconductor component  100  using the first voltage is determined. The condition is met in this aspect when the leakage current falls below a threshold. 
     If the condition is met, a step  412  is carried out. Otherwise, step  408  is carried out 
     In step  412 , the operation of semiconductor component  100  using second voltage U 2  is ended. 
     Step  402  is then carried out. 
     Semiconductor component  100  may thus be operated as long as possible. 
     Semiconductor component  100  may be heated during the operation of semiconductor component  100  using second voltage U 2 . The heating may take place continuously during the operation using second voltage U 2 . The heating may take place with interruptions during the operation using second voltage U 2 . The heating may take place for a shorter time period than the operation using the second voltage. 
     Semiconductor component  100  may be heated in particular to a temperature of 200° C. during the operation of semiconductor component using second voltage U 2 . 
     Semiconductor component  100  may be heated during the operation of the semiconductor component using second voltage U 2  to a temperature which is higher than a temperature of semiconductor component  100  during the operation of the semiconductor component using first voltage U 1 . 
     Semiconductor component  100  may be operated using a second voltage U 2  higher than first voltage U 1 . 
     If dielectric layer  106  includes defects D 2  of the second defect type, the method may provide that their movement in dielectric layer  106  or their positions are taken into consideration in the determination of the limiting values for the durations or in the determination of the thresholds for the leakage currents. 
     In one aspect, the limiting value for the duration is determined in such a way that defects D 2  of the second defect type are moved into a predefined position in dielectric layer  106 . In one aspect, the limiting value for the duration is determined in such a way that defects D 2  of the second defect type do not accumulate at the interface. The limiting value may be selected so that most defects D 2  of the second defect type do not accumulate in the interface, it not being precluded that some defects D 2  of the second defect type, i.e., fewer in relation thereto, accumulate in the interface. In one aspect, the limiting value for the duration is determined in such a way that defects D 2  of the second defect type accumulate in the interface. The limiting value may be selected such that most defects D 2  of the second defect type accumulate in the interface, it not being precluded that some defects D 2  of the second defect type, i.e., fewer in relation thereto, do not accumulate in the interface.