HU209212B - Arrangement for measuring heat-variable dc and/or high frequency parameters of the semiconductor devices in the course of operation and thermostat for operating and/or measuring semiconductor devices in a filed of variable temperature - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention relates to a measuring arrangement for measuring the temperature-dependent DC and / or high frequency parameters of semiconductor devices during operation, which is a measuring arrangement of a digital computer parameter measuring device, a temperature controller, a temperature sensor and a controllable power supply, as well as a thermostat and two thermometers in the thermostat, a semiconductor device connector and a heater. equipped with a semiconductor support plate connected to the thermostat cover, where the parameter measurement device is in the scope of EN 209 212 BA: 10 pages (including 3 sheets)

Description

The signal output of the thermometer and the setpoint input of the thermostat and the control input of the power supply are connected to the computer via an interface. It is an object of the present invention that a semiconductor plate mounted on the housing of a thermostat (T) of 370 W / mK or better, preferably copper, with spacers (9) of 30 W / mK or less, has a heating element and a battery holder made of a block of metal containing two thermometers (21, 24) and a sample cavity (26) of good shape and having a heat cavity (26) of a shape corresponding to the housing of the semiconductor device (20) to be measured, preferably copper consisting of a sheet (13) of a weight of 5 to 10 grams of the metal block, the battery support sheet (13), the thermometers (21, 24), and the elements and the semiconductor device (20), a minimum of 370 W / mK heat-conducting material, preferably copper-plated, with a thermowell inside the thermostat (T) which wraps the semiconductor carrier plate The thermostat (T) is immersed in a liquid refrigerant, preferably liquid nitrogen (6) in the interior of a DEWAR bottle (5) and the semiconductor device (20) is connected via a coaxial cable (14). thermostat (T) for a coaxial connector (3) located externally, from which a coaxial cable (34) to the measuring input (M) of the parameter measuring device, one thermometer (21) to the measuring input of the temperature controller (V) and the other thermometer (24) ), the temperature output of the temperature controller (V) is connected to the heater and an additional heater (F) is connected to the DEWAR cylinder (5), which is connected to the output of the power supply (TE).

SUMMARY OF THE INVENTION The present invention relates to a measuring arrangement by means of which high frequency parameters of dc and transient semiconductor devices (diodes, transistors, etc.) can be automatically determined during operation at various well-defined temperature conditions; on the other hand, a small and low-power thermostat in which a DC, low- and high-frequency parameters can be measured on a semiconductor device encoded over a wide temperature range. The temperature range of the measurements ranges from 77 K to 30 650 K. A positioning accuracy of 1 K and a stability better than 0,3 K.

It is a common task during semiconductor component manufacturing and R&D to measure semiconductor electrical parameters at varying temperatures.

These measurements can be used to determine a number of semiconductor properties, e.g.

- the built-in voltages from the temperature dependence of the current-voltage characteristics;

- from thermally stimulated current measurements, impurities:

- insulating capacity and possible contamination of the applied oxide layers;

- the capacity-voltage curve gives information on the additive concentration;

- Capacity-Time-Temperature Relationship for Deep Level Cross Section and Activation Energy (DLTS);

- the measurement of the high-frequency S-parameters can be used to determine the electrical substitute image of the element and, with variable temperature measurement, to determine its thermal dependence, especially in the case of parasitic elements (eg series resistors).

Each of the known solutions is suitable for one of the measurements listed above.

Patent Nos. 181136 and 182777 (HU) disclose apparatus for performing DLTS measurement. These devices consist of a cryostat that receives the sample to be measured, a DEWAR bottle containing refrigerant, a refrigerant circulation system and electronic measuring equipment, and a weighing computer. The device measures the transient capacitance change of the semiconductor element at different temperatures over a range of 1-30 MHz. These patents employ a thermostat as described below or other known designs.

Other measurement configurations are also known for measuring other parameters of semiconductor elements already listed above.

The semiconductor element to be measured is placed in a heater-cooled thermostat in these devices. Such thermostat designs are described in DDR Patents 220,509 and 263,878. For each of these, the semiconductor element to be measured is placed on a high-density metal plate and this metal plate is heated either directly or by radiant heating, or by a liquid medium passed through a built-in tube coil and controlled by a pumping device. fo40 with liquid nitrogen, cooled.

The prior art devices are inadequate for in-service testing of semiconductor elements at rapidly changing temperature conditions, particularly at frequencies above 100 MHz, and are capable of performing either direct current, 45 or high frequency (below 100 MHz) measurements.

Known thermostats are high in weight, require large amounts of refrigerant and high performance heating, have high heat inertia and are not suitable for women to perform rapid heat changes and are designed to work at a measurement frequency greater than 100 MHz (typically greater than 30-50 MHz). not possible. In the prior art, the flow of refrigerant is solved by moving parts 55, which are often found to fail, since water, carbon dioxide, etc., sometimes enters the liquid nitrogen used as the refrigerant at 77 K. solid state, which damages moving parts.

With the present invention, a measuring arrangement and

HU 209 212 Β A thermostat is designed to measure semiconductor cells of various enclosures (from diode to IC) up to 2 GHz, from 770 K to 650 K at rapidly changing temperatures.

In one aspect, the present invention relates to a measuring arrangement for measuring the temperature-dependent DC and / or high frequency parameters of semiconductor devices in operation, comprising a digital computer, a parameter measuring device, a temperature controller, a thermometer and a controllable power supply; , where the signal output of the parameter measuring device, the signal output of the temperature meter and the setpoint input of the thermostat and the control input of the power supply are connected to the computer via an interface. It is an object of the present invention to provide a housing made of a metal having a thermal conductivity of 370 W / m.K or better, preferably copper. A semiconductor support plate attached to spacers of 30 W / mK or less with a heat conductivity metal, with a sample hollow 370 W / mK of a metal block containing the radiator and two thermometers and a well-coupled connection therewith. consisting of a material of better conductivity material, preferably of copper, wherein the total mass of the metal block, the element, the thermometers of the heater is 5-10 grams, and these elements and the semiconductor device, a material of at least 370 W / mK, preferably is placed in a heat-insulated pot with a copper-walled thermostat inside the thermostat. The thermostat is immersed in a liquid refrigerant inside a DEWAR bottle, preferably liquid nitrogen, and the semiconductor device is connected via a coaxial cable to a coaxial connector located on the outside of the thermostat, from which a thermometer to a temperature controller, The thermometer is connected to the signal input of the thermometer. The output of the thermostat control signal is connected to the heater and an additional heater is located in the DEWAR cylinder which is connected to the output of the power supply.

The present invention also relates to a thermostat for actuating and / or measuring a semiconductor device in a variable-temperature space having a metal lid and a sealed receptacle having a metal semiconductor plate having a heat reflector, a heater and a thermometer attached thereto, and has a thermometer lead and a signal input and output. SUMMARY OF THE INVENTION The semiconductor backing plate is made of a metal plate made of at least two thermally conductive metal materials, preferably stainless steel, of 370 W / mK or better, preferably copper, to the cover, and a metal having a thermal conductivity of 370 W / mK or better, preferably copper, and a heat cavity of 370 W / mK or better, preferably copper-bonded to the motherboard, having a sample cavity corresponding to the housing of the semiconductor device. battery compartment. The motherboard is also provided with a semiconductor device connector which forms a closed interior space with a matching thermal conductor pot of 370 W / mK or better, preferably copper, which is located inside the spoil, the battery compartment and the semiconductor device connector. there is a bore in which a thermometer is located separated from it by a wall 0.33 to 1.0 mm thick from its boundary plane towards the battery support plate. The semiconductor device connector is connected by a coaxial cable to the coaxial connector on the cover, such that the coaxial cable (s) is soldered to the contacts of the coaxial connector, while the shielding strap is soldered to the cover and the system board. The thermometers as well as the heater board terminals are connected to a multi-pole connector. There is a heater in the bottom of the motherboard and a heater temperature gauge in a separate groove.

The thermostat of the present invention may also be configured such that a bell of the same material is attached to the cover, preferably welded, and the coaxial connector and the connector are secured to the top of the bell and the coaxial cable or wires leading to the coaxial connector are .

In a further embodiment of the thermostat according to the invention, a water-absorbent absorbent is provided in the space below the heat shield pot in a space separated by a sieve.

Alternatively, the thermostat of the present invention may be provided with a heat sink for the vessel and a tap with a vacuum connector on the lid or bell space.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, in which:

Fig. 1 shows a measuring arrangement according to the invention, a

Fig. 2 shows a thermostat according to the invention, a

Figure 3 shows another embodiment of the thermostat according to the invention.

The measuring arrangement according to the invention is shown in Fig. 1 from a PC with an interface 1, a parameter measuring apparatus M of known design, a temperature regulator V, a thermometer H, a TE power supply and a liquid nitrogen submerged in DEWAR bottle 5. It consists of T thermostat. The interface input 1 is connected to the signal output (s) of the parameter meter M, the operating signal output of the temperature controller V, the signal output of the temperature meter H, and to its outputs the control input of the parameter meter M, the reference input of the temperature controller V and the control input.

The amount of liquid nitrogen refrigerant 6 contained in the DEWAR flask 5 is such that the

EN 209 212 je Cover 2 containers, 1 lid, and a portion of the 31 bells attached to the thermostat T with heat sink. At the top of the bell 31 above the surface of liquid nitrogen 6 is the multipole connector 4, which is connected to the thermometer terminals inside the thermostat T and the heater supply lines, while the coaxial connector 3 is connected to the semiconductor device terminals to be measured. Figures 2 and 3 illustrate the structure and internal arrangement of the T thermostat. The thermometer in thermostat T through connector 4 and line 32 to the signal inputs of temperature gauge H, thermometer for heating plate temperature through connector 4 and through two wires of line 33 to temperature input V of temperature controller V, output of temperature control actuator V to other wires 33 and 4 Connects to the radiator inside the thermostat T via a connector. In the Dewar bottle 5 there is a heater F at the bottom, the terminals of which are connected to the output of the power supply TE. The T thermostat with heat sink 25 is located on 8 racks on the bottom of the 5 Dewar bottles. At the top of the bell 31 of the thermostat T is attached a pin 29 with a vacuum connection which is connected directly or through a suction pipe to the interior of the thermostat T,

Figure 2 shows one possible embodiment of the T thermostat according to the invention. The T thermostat of this design is shown in the measuring arrangement shown in Figure 1. The thermostat T consists of a copper vessel 2, a matching copper lid 1 and internal elements within the vessel 2. A seal 7 provided in the groove of the upper part of the vessel 2 secures the gas-tight connection of the lid 1. The cover 1 is provided with a protruding bell 31 and wires 35 pass through the connector 4 attached to the upper face of the bell 31, the suction tube 28 to the pin 29 and the coaxial cable 14 through the bores 31 of the cover 1. inside. Inside the vessel 2 with outer heat sinks 25 to the lid 1, a metal of low thermal conductivity, e.g. made of stainless steel 9 with high heat conductivity material fastened by spacers, e.g. the copper base has 10 round motherboards. The top of the base plate 10 has a recess in which a heating plate 22 and a heat mirror 27 are located above it. The base plate 10 is provided with a hole in which a thermometer 21 is provided. This thermometer 21 is a semiconductor diode. A heat shield pot 11 made of a material of high thermal conductivity is fitted to the side panel of the base board. Inside the heat shield pot 11, the stump 12 is attached to the bottom of the base plate 10 and is provided with a battery support plate 13 having a sample cavity 26 adapted to the housing of the semiconductor device 20 to be measured. The total weight of the heat shield pot 11, the stump 12, the thermometer 24, the battery support plate 13, the base plate 10, the thermometer 21 and the heating plate 22 may be from 5 to 10 grams. Inside the heat shield pot 11, a half conductor connector 17 is attached to the base plate 10 by a connector holder 16, to which the terminals of the semiconductor device 20 can be soldered or plugged. The contacts of the half conductor connector 17 are soldered to the coaxial cable 14 through the holes in the base plate 10 and the cover 1. The shielding stockings of the coaxial cable 14 are soldered to the base plate 10 and the cover 1. In the block 12, there is a hole 23 separated from the lower plane of the block 12 in contact with the upper plane of the battery compartment plate 13 by a wall 23 having a thermometer 24 for measuring the temperature of the semiconductor device 20 (a resistance thermometer Pt). . At the bottom of the vessel 2, which is provided with heat sinks 25, is a water-absorbent absorbent 19 separated from the upper space by a sieve 18. The wires 35 connect the thermometers 21 and 24 and the heater plate 22 to the connector 4. The closed interior space of the vessel 2 is connected to the tap 29 having a vacuum connection via a suction pipe 28.

When designing a thermostat, a metal with a high thermal conductivity of 370 W / m.K or better, e.g. copper; as a material with a low thermal conductivity, a material with a thermal conductivity of 30 W / m.K or less, e.g. stainless steel is used.

Figure 3 shows another embodiment of the T thermostat according to the invention. In this embodiment, the arrangement of the components inside the vessel 2 is the same as that shown in Figure 2, except that the bell 31 is not connected to the lid 1 (no bell 31) and thus the connector 4 is directly attached to the lid 1. the pin 29 and the 3 coaxial connectors. This solution requires that the coaxial connector 3 and the connector 4 be sealed as they are located below the surface of the refrigerant. The multipole connector 4 is connected to the thermocouple terminals 21 and 24 inside the thermostat T and to the heater 22 as the heater board, while the coaxial connector 3 is connected to the terminals of the semiconductor device 20 to be measured directly or indirectly to the terminals 17 14 coaxial cables. In the thermostat T, the semiconductor device 20 is made of a material with good thermal conductivity, e.g. inside the copper heat shield pot 11 is placed on a battery compartment 13 provided with a radiator and mounted on a copper metal block so that the sample compartment 13 is arranged in a sample cavity 26 of a shape and size corresponding to the housing 20 of the semiconductor device to be measured. The thermometers 21 and 24 are located in the cavities inside the metal block. The metal block, the battery support plate 13 with good heat coupling, the semiconductor device 20 and the surrounding heat shield pot 11 are made of a material with poor thermal conductivity, e.g. with spacers 9 made of stainless steel and attached to the cover 1 of a thermostat T made of copper or other good heat-conducting material. Connected to the connector 4 are the terminals of the thermometer 24, the heating plate 22 and the thermometer 21 measuring its temperature. The tap 29 allows vacuuming or filling with inert gas.

Again, the total weight of the debris 12, the heat shield 11, the thermometer 24, the battery compartment 13, the base plate 10, the thermometer 21 and the heating plate 22 may be 510 grams.

HU 209 212 Β

The low thermo inertia that is important for the design of the T thermostat is achieved by having a combined weight of 10 grams (or less) of the thermometers 21 and 24, the heater 22, the all heat shield pot, the base plate 10, the stump 12 and the battery tray 13. The air gap between the debris 12 and the battery support plate 13 and the heat shield pot 11 or between the heat shield pot 11 and the vessel 2 should be minimal (at most 1 mm). The size of the thermostat T is thus determined by the semiconductor device 20 having the largest case to be measured, since it must be located in the sample cavity 26 of the battery compartment 13 in the interior space formed by the motherboard 10 and the heat shield pot. the required air gap (0.51,5 mm) is maintained.

The measuring arrangement according to the invention measures as follows:

The thermostat T is disassembled and the semiconductor device 20 to be measured is inserted into the sample cavity 26 of the battery compartment 13 and its terminals are connected to the semiconductor device connector 17. Place all the heat shield pots on the motherboard 10. A fresh absorber 19 is placed on the bottom of the vessel 2, the screen 18 is placed, the gasket 7 is placed, and the lid 1 is placed on the vessel 2 and the thermostat T is sealed. Place the rack 8 on the bottom of the Dewar bottle 5, place the thermostat T, and then connect the coaxial connector 3 to the parameter measuring device M using the coaxial cable 34, then connect the conductor 33 to thermostat V and conductor 32 to thermometer H. Subsequently, the Dewar bottle 5 is filled with liquid nitrogen 6 so that it covers the lid 1 and only the upper part of the bell 31 protrudes. After the measurement arrangement has been prepared in this way for the given measurement task, the measuring process is already controlled by the PC in accordance with the given task.

The measurement sequence starts when the thermometers 21 and 24 indicate the setting of the temperature equilibrium. Given the low heat capacity of the T thermostat, this is a very fast process. The actual measurement temperature is provided by the PC to the temperature controller V, which heats the motherboard 10 with current applied to the heater board 22, thereby integrally affecting the spool 12 and the battery compartment 13. The heat mirror 27 reduces the amount of heat dissipated. All heat shield pots and spacers 9 made of low heat conductivity material minimize the heat inertia of the interior. The thermometer 21 measures the temperature of the motherboard 10 and is a control signal of the two-position thermostat V. Damage 12 smooths out temperature fluctuations due to dual position control. The actual temperature of the semiconductor device 20 is measured by the thermometer 24. The measuring period of the M parameter measuring device is always set after a temperature equilibrium has been set, which is a quick process due to the low thermal inertia. The low thermal inertia makes it possible to use a small amount of refrigerant.

To achieve a temperature range above room temperature, the liquid nitrogen 6 is removed by a heater F driven by a TE supply unit. In this case, at the command of the PC, the power supply TE supplies power and the heater F boils the liquid nitrogen 6 and, given its small amount, is also a fast process.

Given that all the connectors of the semiconductor device 20 can be wired, testing can be performed under any operating conditions, including during operation. In some cases, it may be necessary to perform the test under vacuum, in which case the interior of the thermostat T can be aspirated through the tap 29 and suction pipe 28. The use of a suitable semiconductor device connector 17 and soldering 15 attached to the motherboard 10 and the cover 1 by means of a coaxial cable 14 and a coaxial connector 3 ensures the availability of the GHz range.

The measuring arrangement and thermostat according to the invention have the following advantages:

- be capable of measuring both encapsulated and unenclosed semiconductor devices,

- semiconductor devices can be measured during operation and at rapidly changing temperatures;

- DC and high frequency (up to 2 GHz) measurements can be made;

- due to the low weight and low thermal inertia the measuring temperature can be changed quickly;

- Suitable for continuous measurement from 77 K to 650 K;

- minimal refrigerant requirements;

- no refrigerant pump required;

- automated measurement and evaluation possible;

- suitable for measurement under vacuum or in a controlled atmosphere;

- the following measurements can be made and properties related to the following semiconductor determined;

- the built-in voltages as a function of the temperature dependence of the current-voltage characteristics;

- pollutants from thermally stimulated current measurements;

- the peelability and possible contamination of the applied oxide layers;

- the capacity-voltage curve gives information on the additive concentration;

- Capacity-Time-Temperature Relationship for Deep Level Cross Section and Activation Energy (DLTS);

- the measurement of the high-frequency S-parameters can be used to determine the electrical substitute image of the element and, with variable temperature measurement, to determine its thermal dependence, especially in the case of parasitic elements (eg series resistors).

It will thus be seen that the object of the present invention is achieved by the present invention.

Claims (5)

1. Measuring arrangement for measuring the temperature-dependent DC and / or high-frequency parameters of semiconductor devices during operation, The digital computer includes a parameter measuring device, a temperature controller, a temperature meter and a controllable power supply, as well as a thermostat and a semiconductor support plate with a thermometer and two thermometers in the thermostat, a semiconductor device connector and a heater, the setpoint input of the temperature controller and the control input of the power supply are connected to the computer via an interface, characterized in that the cover of the thermostat (T) is 370 W / mK or better, preferably copper, 30 W / mK or worse a semiconductor carrier plate attached to the thermally conductive metal spacers (9) by means of a block of metal containing the radiator and the two thermometers (21, 24) and a consisting of a battery support plate (13) made of a 370 W / mK or better thermal conductivity material, preferably copper, having a sample cavity (26) of a shape corresponding to the housing of the semiconductor device (20) to be measured; ), the thermometers (21, 24), the total weight of the heater is 5 to 10 grams, and the thermostat (T) with these elements and the semiconductor device (20) with a wall of at least 370 W / mK heat conducting material, preferably copper the thermostat (T) is immersed in a liquid refrigerant, preferably liquid nitrogen (6) in the interior of a DEWAR bottle (5), and the semiconductor device (20) is coaxial (14) is connected to the coaxial connector (3) on the outside of the thermostat (T), from which the measuring input (M) of the parameter measuring device is connected via a coaxial cable (34) one of the thermometers (21) is connected to the temperature input of the temperature controller (V), the other thermometer (24) is connected to the signal input of the temperature meter (H); the control signal output of the temperature controller (V) is connected to the heater and an additional heater (F) which is connected to the power supply (TE) output. 2. A thermostat for actuating and / or measuring a semiconductor device in a variable temperature space having a metal lid and a receptacle sealed thereto, comprising a metal semiconductor support plate with a radiator and a thermometer attached thereto and a thermometer of the vessel. and signal input and output, characterized in that the semiconductor support plate is provided with a 370 W / mK heat exchanger (9) attached to the cover (1) by at least two heat conductive metal spacers (9), preferably stainless steel. or a heat-conducting metal (10) made of a better heat-conducting metal, preferably copper, and a heat-conducting metal (12), preferably copper-bonded to said motherboard (10) with good thermal coupling, and to this (12), good semiconductor device case with good thermal coupling consisting of a heat-conductive metal support plate (13) having a sample cavity (26) of 370 W / mK or better, and a semiconductor device connector (17) associated with the motherboard (10), with a thermally conductive material 370 W / mK or better, preferably a copper heat shield pot (11), forms a closed interior space which is housed inside the debris (12), the battery support plate (13) and the semiconductor device connector (17); separated by a wall (0.3) having a thickness of 0.3 to 1.0 mm from its boundary plane towards the battery support plate (13), in which a thermometer (24) is located and the semiconductor device connector (17) with a coaxial cable (14). ) is connected to the coaxial connector (3) on the cover (1) such that the coaxial cable (14) has a force (s) on the contacts of the coaxial connector (3), while the sleeve is soldered to the cover (1) and base plate (10). attached, the terminals of the thermometers (21, 24) and the heater (22) are connected to a multi-pole connector (4), the heater being formed as a heater (22) in the recess of the base plate (10) and the thermometer of the heater (21) and the combined weight of the stump (12), the thermometers (21, 24), the battery support plate (13) and the heating plate do not exceed 5-10 g. Thermostat according to Claim 2, characterized in that a cover (31) of the same material is attached to the cover (1), preferably welded thereto, and the coaxial connector (3) and the connector (4) are the bell (31). is mounted on top, and the coaxial cable (14) leading to the coaxial connector (3) and the wires (35) leading to the connector (4) are guided through the holes of the cover (1). Thermostat according to claim 2 or 3, characterized in that the vessel (2) has a water-absorbent absorbent (19) in the space below the heat-shielding pot (11) separated by a sieve (18). 5. Thermostat according to any one of claims 1 to 3, characterized in that the vessel (2) has heat sinks and a pin (29) with a vacuum connection on the lid (1) or on the top of the bell (31).