TWI701764B - Process to insulate defect cells of electronic component and electronic component with self-insulating cells - Google Patents

Abstract

A method for insulating a defective unit cell (210) of an electronic component (200), including the following steps: generating a unit cell (210) on a semiconductor substrate (280) (step 100); in the unit cell (210) Create an electrical connection with at least two terminals (220) (230) (step 110); apply a polymer layer to the electronic component (200) (step 120); apply a measurement voltage to the two terminals (220) (230), so when a unit cell (210) is faulty, at least one of the electrical connections is exposed due to the decomposition of the polymer layer in the region of the faulty unit cell (210) (step 150); The exposed electrical connections are selectively etched away (step 160); the polymer layer is removed (step 170). In addition, it also relates to an electronic component (200), which has a plurality of unit cells (210) on a semiconductor substrate (280), wherein each unit cell (210) has at least two terminals (220) (230). ) The electrical connection part is characterized by: When the unit cell (210) is faulty, its electrical connection to at least one terminal (220) (230) is interrupted.

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Description

Method for insulating a defective unit cell of an electronic component and electronic component having a unit cell with automatic insulation

The present invention relates to a method for insulating a faulty cell (Zelle, English: cell) of an electronic component and an electronic component. The faulty cell can be insulated by itself.

Electronic components such as side power switches or GaN transistors can be manufactured inexpensively on a silicon substrate. In fact, the substrate will never be defect-free, and will fail during various parts of the process. A common fault in electronic components is a short circuit, where the current-carrying terminal is on the chip side due to substrate or process defects. connection. Components with such failures cannot be used in practice and must be selected by screening. For this reason, the electronic components must be colored (inken) before being cut or packaged.

The disadvantage here is: the whole selection of electronic components, although the short circuit is mostly limited to one or a few unit cells.

The purpose of the present invention is to increase the yield of functional electronic components.

The method for insulating a defective unit cell of an electronic component of the present invention includes: generating a unit cell on a semiconductor substrate. The electronic component includes a plurality of unit cells (they have the same manufacturing tolerance), and these unit cells There are several individual components of the same kind, such as power transistors or Container or DRAM. "Same type" refers to individual components of the same structure type. These unit cells are connected to at least two terminals or wires in a conductive manner, and a polymer layer (especially a thermally decomposable polymer layer) is applied to the electronic component. This method additionally includes applying a measuring voltage to the At least two terminals, so when there is a defective unit cell, one of the electrical connections can be exposed by decomposing the polymer layer in the area of the defective unit cell, and the at least one exposed electrical connection The part is selectively etched, and then the remaining polymer layer is removed.

The advantage here is that during manufacture, the defective unit cell can be insulated on the electronic component in a simple manner, so that the component does not need to be screened out entirely.

In a further feature, at least two contact surfaces are created to apply the measurement voltage. They are produced using Photolithographie and etching steps.

The advantage here is that the contact is very smooth.

In another design, the unit cell is turned off using a control voltage.

The advantage here is that the unit cell can also have active individual components. In other words, it is a self-conducting component, such as a power transistor. If this method is not used, a self-disconnecting component can also be used.

The electronic component has a plurality of unit cells, and each unit cell has at least two electronic connection parts connected to at least two terminals.

According to the present invention, in the case of a cell failure, the electrical connection to at least one terminal is disconnected.

The advantage here is that even if some unit cells fail, the electrical component can still be used and does not need to be screened out.

In a further feature, the unit cell types of the electronic components are the same.

The advantage here is that electronic components can be used for high-power applications.

In a further feature, the unit cell has power transistors, especially HEMTs.

The advantage here is that a power switch with high power compatibility can be produced in this way.

In yet another embodiment, the unit cell includes a capacitor.

The advantage here is that the unit cell can also have passive components.

In still another embodiment, the unit cell includes DRAM, and the advantage here is that the damaged area can be effectively insulated.

In a further feature, the disconnection of the electrical connection has a characteristic form.

The advantage here is that the type of fault and its temperature can be determined by using the edge trend of the disconnected electrical connection.

In another embodiment, the semiconductor substrate has gallium nitride.

Other advantages can be seen in the description of the following embodiments or the appendix of the scope of patent application.

The present invention is illustrated by the following embodiments and drawings.

(100):Procedural steps: Generate a unit cell on the semiconductor

(110): Procedure steps: connect the unit cell to at least two terminals and generate electrical connections

(120): Procedure steps: apply polymer layer

(130): Procedure steps: produce at least two contact surfaces

(140): Procedure steps: turn off the normally closed power transistor

(150): Procedure steps: apply the measured voltage to at least two terminals

(160): Procedure steps: Selectively etch the loose electrical connections

(170): Procedure step: remove polymer layer

(200): Electronic components

(210): unit cell

(220): Source Terminal

(230): Die terminal

(250): first contact surface

(260): second contact surface

(270): Fault location

(280): Semiconductor substrate

(300): Electronic components

(310): unit cell (normal)

(320): unit cell (faulty)

(330): Short circuit

(380): Semiconductor substrate

Fig. 1 is a method of insulating a faulty cell of an electronic component, Fig. 2 is a top view of the electronic component during manufacture, and Fig. 3 is a top view of the electronic component after the manufacturing process is completed.

Figure 1 shows a method of insulating a faulty cell of an electronic component. The method starts with step (100), where the unit cell is generated on a semiconductor substrate. Here, the electronic component includes several (especially parallel) unit cells. Here, the unit cells of the electrical components have the same function. To generate these unit cells, The department uses standard procedures. In a subsequent step (110), the unit cell is conductively connected to at least two terminals, and an electrical connection portion is generated. The two terminals are conductive terminals in the operation of the electronic component. In a subsequent step (120), a thermally decomposable polymer layer (for example, a thermally decomposable polymer TDP) is applied to the electronic component. In a subsequent step (150), a measuring voltage is applied to the at least two terminals, wherein contact means (especially probes) are passed through the polymer layer until electrical contact is made with the terminals. Here, the measured voltage generates a current that flows through the unit cell. If the unit cell is intact, a predetermined leakage current will flow. This predetermined leakage generates a small amount of heat. In the case of a self-conducting transistor, the transistor must use the control voltage (it passes through a third contact). In) open circuit. However, if the unit cell has a fault, a higher leakage current flows, and it generates high heat energy related to the fault. A common fault in this type of unit cell is a short circuit. Here, the heat generated in a fault situation is several times larger than in an intact unit cell, especially ten times. This generated heat energy therefore increases the temperature of the unit cell, which may therefore damage or destroy the unit cell.

Therefore, the measurement voltage is selected so that the heat generated in the short-circuited unit cell is sufficient to raise the unit cell temperature high enough to reach or exceed the decomposition temperature of the polymer layer. In other words, the temperature of the unit cell exceeds that of the polymer layer. Decomposition temperature, so the electrical connections in the area of the faulty unit cell loosen. Here, the decomposition temperature of the polymer layer must be below the breakdown temperature (melting point) of aluminum. Because most of the electrical connections of electrical components have aluminum. Therefore, the decomposition temperature of the polymer used is below 600°C, especially in the range of 200°~300°C. In another modification, the electrical connection part of the electrical component can be made of copper, so that the decomposition temperature of the polymer is below 1000°C. In the subsequent step (160), the loosened electrical connection is selectively etched, for example, using a wet chemical aluminum etching solution (ANPE) or using a dry chemical plasma process. Here, the polymer layer functions as an etching shield. In other words, the electrical connection part (also known as the conductive metal-plated part) is at a position where there is no longer a polymer. Places or locations subject to high temperature loads due to malfunctions are removed. In a subsequent step (170), the remaining polymer layer is, for example, removed by heating to above the decomposition temperature (about 200-300°C). Therefore, the defective unit cell on the electronic component is insulated. In other words, the defective unit cell on the final product or wafer remains insulated.

The method of the present invention is mainly suitable for power electronics side components of silicon and gallium nitride power electronic technology such as LDMOS, but also suitable for manufacturing components such as silicon capacitors or DRAM.

This method can also be used for vertical transistors on silicon substrates, such as SiIGBT, Si-MocFet, or silicon substrates such as SiC-MosFet, SiC-JFet. But here, the method must be implemented on the front side of the wafer.

In one embodiment, the unit cell has a power transistor that is open by itself, in other words, the power transistor is a normally open circuit. In this case, the two terminals represent the drain terminal and the source terminal.

In another embodiment, the unit cell has active individual elements or components. They are automatically turned on during normal operation. Such active components are, for example, power transistors that automatically turn on. In other words, the power transistor is normally closed. In this case, another step (140) is performed after step (120) and before step (150), in which the power transistor or power transistor unit cell is turned off using a negative control voltage (generally a gate voltage) .

Therefore, the implementation of this method has nothing to do with whether the power transistor used is automatically turned on or automatically disconnected in the initial state. In the case of automatic turn-on, it is only necessary to confirm that the gate control voltage (for example, using a third pin) is applied, so that when the method of the present invention is implemented, the power transistor is turned off. This means that the control voltage is selected to turn off the component.

It is also possible to produce at least two contact surfaces in a step after step (120) as needed to make it easier for the contact means to contact the terminal (mainly the drain terminal source terminal), or contact It is better to remove the polymer layer at two locations on the terminal for this purpose.

In another embodiment, the unit cell includes a capacitor or DRAM.

Figure 2 shows a top view of the electronic component (200) after the step (150) in the method of the present invention is completed. For example, the electronic component (200) has three unit cells (210) with power transistors. Here, the unit cells (210) are provided on a semiconductor substrate (280) (such as gallium nitride or silicon), and in this example are connected in parallel or parallel wires. Each unit cell (210) is electrically connected to a source terminal (220) and a drain terminal (230). The electronic component (210) may also have first and second contact surfaces (250) (260) as needed. In the lower unit cell (210), for example, a fault location (270) such as a short circuit is displayed.

Figure 3 shows the electronic component (300) after the method of the present invention is completed. The electronic component (300) has, for example, three unit cells with power transistors connected in parallel, which are set on a semiconductor substrate (380), and the electronic component (300) There are two intact unit cells (310) and an insulating unit cell (320) with a short circuit (330) (the connection between the drain terminal and the source terminal is interrupted).

In another embodiment, the unit cell includes power transistors with high electron mobility, such as HEMT, where the power transistors are connected in parallel in the unit cell, so that a fast power switch can be generated.

(100):Procedural steps: Generate a unit cell on the semiconductor

(110): Procedure steps: connect the unit cell to at least two terminals and generate electrical connections

(120): Procedure steps: apply polymer layer

(130): Procedure steps: produce at least two contact surfaces

(140): Procedure steps: turn off the normally closed power transistor

(150): Procedure steps: apply the measured voltage to at least two terminals

(160): Procedure steps: Selectively etch the loose electrical connections

(170): Procedure step: remove polymer layer

Claims (10)

A method for insulating a defective unit cell (210) of an electronic component (200), including the following steps: generating a unit cell (210) on a semiconductor substrate (280) (step 100); in the unit cell (210) Create an electrical connection with at least two terminals (220) (230) (step 110); apply a polymer layer to the electronic component (200) (step 120); apply a measurement voltage to the two terminals (220) (230), so when a unit cell (210) is faulty, at least one of the electrical connections is exposed due to the decomposition of the polymer layer in the region of the faulty unit cell (210) (step 150); The exposed electrical connections are selectively etched away (step 160); the polymer layer is removed (step 170). Such as the method of item 1 in the scope of patent application, wherein: at least two contact surfaces (250) (260) are generated to apply the measurement voltage. For example, the method according to the first or second item of the scope of patent application, wherein: the unit cell (210) is turned off by a control voltage. An electronic component (200), which has a plurality of unit cells (210) on a semiconductor substrate (280), wherein each unit cell (210) has one connected to at least two terminals (220) (230) The electrical connection part is characterized in that when the unit cell (210) is faulty, the electrical connection part connected to at least one terminal (220) (230) is interrupted. Such as the electronic component of item 4 in the scope of patent application, in which: the unit cell (210) is in the same manner. For example, the electronic component of item 4 or 5 of the scope of patent application, of which: The unit cell (210) has a power transistor. For example, the electronic component of item 4 or 5 of the scope of patent application, wherein: the unit cell (210) includes a capacitor. For example, the electronic component of item 4 or 5 of the scope of patent application, wherein: the unit cell (210) contains DRAM. For example, the electronic component of item 4 or 5 of the scope of patent application, wherein: the interruption of the electrical connection part has a characteristic form. For example, the electronic component of item 4 or 5 of the scope of patent application, wherein: the semiconductor substrate (280) has gallium nitride.

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