KR102701243B1 - Silicon nitride substrate for system semiconductor inspection equipment and manufacturing method thereof - Google Patents

Abstract

In the present invention, a unique blending composition and mixing method of an optimal sintering agent and additive powder that can be sintered at a relatively low temperature and enable a black, defect-free structure are designed, and a vacuum and atmosphere precision pressure control molding equipment that is a modified version of a general low-cost press molding equipment and a vacuum atmosphere sintering equipment that can be sintered at a relatively low temperature and low pressure (near atmospheric pressure) are used to design molding and sintering conditions that allow a silicon nitride ceramic substrate material to have a uniform and dense microstructure, thereby providing a high-quality silicon nitride substrate material that is optimal for high-density, low-defect (low-porosity), and ultra-fine square hole laser processing while utilizing low-cost equipment and production methods.

Description

{Silicon nitride substrate for system semiconductor inspection equipment and manufacturing method thereof}

The present invention relates to a silicon nitride substrate for system semiconductor inspection equipment and a method for manufacturing the same, and more specifically, to a high-quality black densified silicon nitride substrate used as a substrate for ultra-fine square hole laser processing, which is a core component of system semiconductor inspection equipment, and a method for manufacturing the same at low cost.

As the size of semiconductors continues to shrink due to the recent development of semiconductor circuit integration technology, inspection devices for semiconductor chips are also required to have high precision. Integrated circuit chips formed on semiconductor wafers through the wafer fabrication process are classified into good and bad products through electrical characteristic inspection (Electrical Die Sorting; EDS) performed on the wafer.

Electrical characteristic testing generally uses a testing device consisting of a tester responsible for generating test signals and determining test results, a probe station responsible for loading and unloading semiconductor wafers, and a probe card responsible for electrically connecting the semiconductor wafer and the tester.

Among these, the probe card is mainly manufactured by bonding probe pins to a ceramic substrate formed by forming circuit patterns, electrode pads, via electrodes, etc. on a ceramic green sheet, laminating them, and then firing them.

In conventional semiconductor inspection equipment, machinable ceramics were mainly used as probe guides when using circular probes, but recently, system semiconductor inspection equipment is moving toward using MEMS-type square probes to measure high-density, ultra-high-speed semiconductors. At this time, ultra-fine square hole processing of tens of microns in the probe guide substrate to support the square probe is possible only through laser processing, and the only material suitable for withstanding this laser processing is a silicon nitride ceramic substrate with high density, low defects (low porosity), and high thermal shock resistance.

However, since silicon nitride powder itself is a difficult-to-sinter material, basic sintering aids such as alumina, yttria, and ceria and carbon or carbide-based black additives are basically added to sinter silicon nitride ceramics for sintering. However, it is very difficult to secure manufacturing process conditions in which the silicon nitride does not decompose and the additives do not cause defects and disrupt the dense microstructure. In particular, in order to create a silicon nitride ceramic substrate with the characteristics of high density, low porosity, and high thermal shock resistance as described above, expensive equipment such as HP (Hot Press), GPS (Gas Press Sintering), and HIP (Hot Iso-static Pressing) must be used for molding and sintering after the powder process, at high temperatures of 1800 to 1900℃ or higher and high pressures of tens of atmospheres. This requires high costs not only for the equipment construction costs but also for the manufacturing process.

Silicon nitride ceramics are ceramic materials suitable for extreme environments due to their excellent physical and mechanical properties, including high strength, high fracture toughness, and high thermal shock resistance. However, the raw materials and methods for producing ceramic bodies used in them are difficult and expensive, which has limited their application and market.

However, with the recent development of industry, the use of silicon nitride ceramics is increasing significantly in areas such as automobiles, solar energy, machinery, and semiconductors, as well as in the existing tool field, in order to maximize its effectiveness even though it is expensive.

In the semiconductor field, semiconductor integration technology has been further developed in response to market demands for a dramatic increase in semiconductor storage capacity and response speed, leading to increasingly nano-sized semiconductor circuit line widths. Accordingly, semiconductor testing equipment and testing jigs that test these have also evolved to nano-size the test probe size and change the shape of the test probe to increase response speed.

In order to achieve this purpose in semiconductor inspection equipment, a MEMS type probe must be used, and the existing circular probe needs to be changed to a square one to increase the current density. At the same time, thousands of ultra-fine square holes must be machined in the probe guide where the ultra-fine square probe is inserted and supported. At this time, the machinable ceramic material for the probe guide that supports the existing probe has limitations in speed and quality in machining ultra-fine square holes of tens of microns. Therefore, the only alternative currently used as a probe guide for an ultra-fine square probe is a silicon nitride substrate, which is suitable for laser ultra-fine square hole machining due to its high density, low porosity, and good thermal shock resistance.

Accordingly, in the present invention, instead of using a molding and sintering method using high temperature, high pressure, and expensive equipment, the optimal sintering agent and oxide-based additive composition are applied to silicon nitride powder, which is a difficult-to-sinter material, to design an optimal sintering agent and additive powder mixing composition and mixing method that enable a silicon nitride ceramic substrate material to be sintered at a relatively low temperature and have a black structure with few defects. In addition, by designing molding and sintering conditions that allow the silicon nitride ceramic substrate material to have a uniform and dense microstructure using a precision pressure control molding equipment modified from a general low-cost press molding equipment and a nitrogen atmosphere sintering equipment capable of sintering at a relatively low temperature and low pressure (near normal pressure), the present invention was completed by developing a high-quality silicon nitride substrate material that is optimal for high-density, low-defect (low porosity), and ultra-fine square hole laser processing while using low-cost equipment and production methods.

The technical problem to be solved in the present invention is to provide a high-quality black densified silicon nitride ceramic substrate that is optimal for ultra-fine square hole laser processing for a probe guide.

In addition, another technical problem to be solved in the present invention is to provide a method for manufacturing the high-quality silicon nitride ceramic substrate at low cost rather than at high temperature, high pressure and high cost as in the past.

In order to solve the above technical problem, the present invention provides a mixed powder for a silicon nitride ceramic substrate, which is manufactured by adding a mixed powder comprising 71 to 95 wt% of silicon nitride powder, 1 to 5 wt% of alumina, 1 to 5 wt% of yttria, 1 to 5 wt% of magnesium oxide, 1 to 7 wt% of silicon oxide, and 1 to 7 wt% of titanium oxide: isopropyl alcohol: silicon nitride balls in a weight ratio of 1:4:2, mixing at a ball mill rotation speed of 30 to 50 RPM for 24 to 96 hours, drying, and then filtering through a 100 to 150 μm sieve.

In order to solve the other technical problems mentioned above, the present invention provides a method for manufacturing a silicon nitride substrate, characterized by including the following steps:

(S1) A step of blending 71 to 95 wt% of silicon nitride powder, 1 to 5 wt% of alumina, 1 to 5 wt% of yttria, 1 to 5 wt% of magnesium oxide, 1 to 7 wt% of silicon oxide, and 1 to 7 wt% of titanium oxide, more preferably, a step of blending 79 to 91 wt% of silicon nitride powder, 1.5 to 3.5 wt% of alumina, 1.5 to 3.5 wt% of yttria, 2 to 4 wt% of magnesium oxide, 2 to 5 wt% of silicon oxide, and 2 to 5 wt% of titanium oxide;

(S2) A step of mixing the above mixed powder: isopropyl alcohol: silicon nitride balls in a weight ratio of 1:4:2, mixing at a ball mill rotation speed of 30 to 50 RPM for 24 to 96 hours, and then drying to obtain a uniform mixed powder;

(S3) A step of forming a molded body using a vacuum atmosphere precision pressure control molding equipment modified from a low-cost press molding equipment, with the above mixed powder, at a maximum pressure of 50 MPa to 125 MPa per unit area, with a pressure cycle of 1 to 5 minutes of pressure increase, 3 to 8 minutes of maximum pressure, and 1 to 5 minutes of pressure reduction; and

(S4) A step of sintering the above-mentioned molded body in a nitrogen atmosphere sintering furnace at a low pressure (near normal pressure) of 800 torr (1.1 bar) at 1700 to 1750°C for 4 to 7 hours to obtain a silicon nitride substrate.

In addition, the present invention provides a silicon nitride substrate for system semiconductor inspection equipment manufactured according to the above method.

Preferably, the silicon nitride substrate has a density of 3.2 g/cm ³ or more and is characterized by low defects (low porosity: no more than one pore defect having a diameter of 30 μm or more).

In addition, the present invention provides a bending control heat treatment method of a silicon nitride substrate that significantly eliminates bending defect rate during thin plate polishing in order to obtain optimal silicon nitride substrate flatness for use as a probe guide for system semiconductor inspection equipment using the silicon nitride substrate.

Preferably, the method is characterized in that the silicon nitride substrate, which has been subjected to bending due to processing stress during plate polishing, is heat treated at 1400°C for 4 to 6 hours while applying a load of 3 kg or more using a heat treatment jig that has been processed to a flatness of 0.01 mm or less in a vacuum nitrogen atmosphere heat treatment furnace.

In this way, the present invention devised a unique mixing method and composition of an optimal sintering agent and additive powder that can be sintered at a relatively low temperature and enable a black structure with few defects, and by using a vacuum atmosphere precision pressure control molding equipment modified from a general low-cost press molding equipment and a nitrogen atmosphere sintering equipment that can be sintered at a relatively low temperature and low pressure (near normal pressure), the molding and sintering conditions that allow a silicon nitride ceramic substrate material to have a uniform and dense microstructure were devised, and a high-quality silicon nitride substrate material that is optimal for high-density, low-defect (low-porosity), and ultra-fine square hole laser processing was developed while using low-cost equipment and production methods.

The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the contents of the invention described above, serve to further understand the technical idea of the present invention; therefore, the present invention should not be interpreted as being limited to matters described in such drawings.
Figure 1 is a schematic diagram of a low-cost vacuum atmosphere control and precision pressure/speed control press forming device.
Figure 2 is a comparative photograph of the microstructure of the substrate surface according to the mixing composition and sintering temperature.
Figure 3 shows an example of the degree of substrate bending according to the measurement location and TTV (flatness) measurement range within a 100*100 silicon nitride substrate.
Figure 4 is a photograph of the verification of the ultrafine laser square hole machinability of a low-cost, high-quality black densified silicon nitride substrate for system semiconductor measuring equipment developed in the present invention.

The present invention is described in more detail below.

In the present invention, instead of using the conventional high-temperature, high-pressure, expensive equipment-based molding and sintering method, the optimal sintering agent and oxide-based additive composition are applied to silicon nitride powder, a difficult-to-sinter material, to devise an optimal sintering agent and additive powder blending composition and mixing method that enable a silicon nitride ceramic substrate material to be sintered at a relatively low temperature and to have a black structure with few defects.

In addition, the present invention uses a vacuum atmosphere precision pressure control molding equipment modified from a general low-cost press molding equipment and a nitrogen atmosphere sintering equipment capable of sintering at a relatively low temperature and low pressure (near normal pressure) to design molding and sintering conditions that allow a silicon nitride ceramic substrate material to have a uniform and dense microstructure, thereby providing a high-quality silicon nitride substrate material that is optimal for high-density, low-defect (low-porosity), and ultra-fine square hole laser processing while utilizing low-cost equipment and production methods.

In addition, in the present invention, in order to satisfy the silicon nitride substrate specifications optimal for system semiconductor inspection equipment, a process condition for heat treatment before and after thin plate polishing in a process of polishing a silicon nitride substrate material into a thin plate was devised, thereby significantly eliminating the bending defect rate that may occur due to deformation caused by processing stress during thin plate polishing, and developing a stable ceramic substrate manufacturing method.

In general, silicon nitride sintered bodies have a Cermet (WC-Co) structure in which Si3N4 particles are combined with an amorphous glass phase, and their inherent color is ivory to light gray. Therefore, if an element capable of absorbing visible light is included in the amorphous glass phase with a volume occupancy of less than about 10 vol%, blackening is theoretically possible. However, carbon and carbide additives, which are known as representative black additives, are chemically stable and do not react with each other near the sintering temperature. Therefore, if a large amount of these is added, sintering is hindered, and since they have high hardness and large specific gravity, if they exist in an agglomerated state after sintering, there is a possibility that defects may remain on the substrate.

In the present invention, a black additive in the form of Ti-based oxide (TixOy) having hardness and specific gravity similar to silicon nitride was added as an additive which can effectively absorb visible light when reduced with ceramic powder and basic alumina and yttria sintering aids, and at the same time smoothly form a eutectic liquid phase with sintering aids of silicon nitride to contribute to material densification. In addition, in order to enable sintering at a relatively lower temperature, while achieving good dispersion and eutectic with the sintering aid and black additive, Mg-based oxide (MgxOy) and Si-based oxide (SixOy) were added to create a compounding powder.

In the present invention, in order to obtain desired characteristics after molding and sintering of the ternary to hexameric multi-component powders, the characteristics of the powders (purity of 99.9% or higher, particle size between 0.5 and 1 μm), the mixing ratio (mixing composition), and the method of uniformly mixing them are applied.

According to one embodiment of the present invention, after mixing the respective powders in four types of mixing compositions, a substrate was formed using a low-cost vacuum and pressure precision control press forming equipment, and a sintering experiment was conducted at different temperatures in a relatively low-temperature, low-pressure (near normal pressure) atmosphere sintering furnace.

According to one embodiment of the present invention, 71 to 95 wt% of silicon nitride powder, 1 to 5 wt% of alumina, 1 to 5 wt% of yttria, 1 to 5 wt% of magnesium oxide, 1 to 7 wt% of silicon oxide, and 1 to 7 wt% of titanium oxide are blended. More preferably, 79 to 91 wt% of silicon nitride powder, 1.5 to 3.5 wt% of alumina, 1.5 to 3.5 wt% of yttria, 2 to 4 wt% of magnesium oxide, 2 to 5 wt% of silicon oxide, and 2 to 5 wt% of titanium oxide are blended to make a blended powder.

According to one embodiment of the present invention, a mixing method for uniformly dispersing powders is performed by mixing the mixed powder: isopropyl alcohol: silicon nitride balls in a weight ratio of 1:4:2, mixing at a ball mill rotation speed of 30 to 50 RPM for 24 to 96 hours, preferably 48 to 72 hours, and then drying and filtering through a 100 to 150 μm sieve to obtain a uniform mixed powder optimal for molding.

In order to obtain a defect-free microstructure of silicon nitride ceramics, which are generally difficult to sinter, the conventional forming method has been to form the mold using expensive equipment such as isostatic hydraulic pressing (CIP) equipment and hot pressing (HP) equipment. However, in the present invention, by improving low-cost general press forming equipment, the mold is formed by pressurizing in a chamber that creates a vacuum atmosphere to eliminate defects such as micropores during molding and to increase the molding density.

The present invention provides a method for manufacturing a silicon nitride substrate, characterized by comprising the following steps:

(S1) A step of producing a compound powder comprising 71 to 95 wt% of silicon nitride powder, 1 to 5 wt% of alumina, 1 to 5 wt% of yttria, 1 to 5 wt% of magnesium oxide, 1 to 7 wt% of silicon oxide, and 1 to 7 wt% of titanium oxide, more preferably, a step of mixing 79 to 91 wt% of silicon nitride powder, 1.5 to 3.5 wt% of alumina, 1.5 to 3.5 wt% of yttria, 2 to 4 wt% of magnesium oxide, 2 to 5 wt% of silicon oxide, and 2 to 5 wt% of titanium oxide;

(S2) A step of mixing the above mixed powder: isopropyl alcohol: silicon nitride balls in a weight ratio of 1:4:2, mixing at a ball mill rotation speed of 30 to 50 RPM for 24 to 96 hours, and then drying to obtain a uniform mixed powder;

(S3) A step of forming a molded body using a vacuum atmosphere precision pressure control molding equipment modified from a low-cost press molding equipment, with the above mixed powder, at a maximum pressure of 50 MPa to 125 MPa per unit area, with a pressure cycle of 1 to 5 minutes of pressure increase, 3 to 8 minutes of maximum pressure, and 1 to 5 minutes of pressure reduction; and

(S4) A step of sintering the above-mentioned molded body in a nitrogen atmosphere sintering furnace at a low pressure (near normal pressure) of 800 torr (1.1 bar) at 1700 to 1750°C for 4 to 7 hours to obtain a silicon nitride substrate.

In the present invention, since a thin substrate must be formed, a precision pressure control device capable of controlling the pressurization speed, time, etc. with precise resolution is applied to prevent cracks or breakage during pressurization-maintenance-depressurization, and forming is performed under the pressure cycle conditions of pressurization for 1 to 5 minutes, maximum pressure maintenance for 3 to 8 minutes, and depressurization for 1 to 5 minutes at a maximum pressure of 50 to 125 MPa per unit area, preferably 75 to 100 MPa. FIG. 1 is a schematic diagram of a low-cost vacuum atmosphere control and precision pressure/speed control press forming device.

In this field, in order to obtain a microstructure with fewer defects of silicon nitride ceramics, which are difficult-to-sinter materials, the existing sintering method uses a GPS (Gas pressure sintering) method in which gas such as nitrogen is injected into the sintering furnace to make the pressure inside the sintering furnace high-pressure about 30 to 100 bar and sinter at a high temperature of 1900°C or higher, or a HP (Hot press) method in which the temperature is raised to a high temperature of 1900°C or higher and hot pressurization is performed at the same time, which are very high temperature, high pressure, and high cost methods. However, the present invention first applies a unique powder mixing composition that enables sintering at a relatively low temperature while achieving good dispersion and eutectic with a sintering agent and black additives to obtain the characteristics of silicon nitride ceramics and a dense structure, and improves low-cost general press molding equipment to eliminate defects such as micro pores during molding and to increase the molding density by using a press molding device that controls the vacuum atmosphere and controls the precise pressure/speed to sinter an already densified molded body, so that about In a nitrogen atmosphere sintering furnace with a low pressure (near normal pressure) of approximately 800 torr (1.1 bar), a silicon nitride substrate material with a density of 3.2 g/cm ³ or higher and low defects (low pores: 1 or fewer pore defects with a diameter of 30 μm or more) was obtained by sintering at a relatively low temperature of 1700–1750 °C for approximately 4–7 hours.

According to one embodiment of the present invention, the density of the silicon nitride ceramic substrate material was measured after sintering at a relatively low temperature of 1650 to 1800°C for each of the four types of compound compositions, and the number of defects, i.e., pores with a diameter of 30 μm or more, was measured using a three-dimensional vision measuring device for the entire surface of a 100*100 substrate.

In order for a silicon nitride substrate material having a dense microstructure, manufactured by a low-cost molding and sintering method and having a characteristic mixing composition according to the present invention to be applied to a system semiconductor inspection equipment after ultra-fine laser square hole processing, it must be polished into a thin plate of 0.2 to 0.3, and its thickness tolerance and TTV (flatness) must be precise at +/-0.005 mm (10 ㎛) or less and +/-0.02 mm (40 ㎛) or less, respectively. However, when polishing this plate, bending occurs due to deformation caused by processing stress, and in many cases it is impossible to meet this specification. Therefore, the present invention provides a stable ceramic substrate manufacturing method that significantly eliminates the bending defect rate by developing optimal heat treatment process conditions before and after plate polishing.

According to one embodiment of the present invention, the heat treatment process was performed at 1300 to 1500°C for 2 to 5 hours using a heat treatment jig processed to a flatness of 0.01 mm or less in a heat treatment furnace under a nitrogen atmosphere after vacuum, while applying a load of 3 kg or more, and then, using a 3D vision measuring device, the z-axis step from the bottom was measured at 5 points on a 100*100 substrate, and the TTV (flatness) and whether there was a bending defect were determined by measuring whether the maximum and minimum value differences were less than 40 μm (+/- 0.02 mm). According to the present invention, when heat treating was performed at 1400°C for 4 to 6 hours, it was confirmed that the TTV (flatness) value was 30 μm or less and there was no bending defect.

The low-cost, high-quality black densified (high-density, low-pore) silicon nitride substrate developed in the present invention is applied as a probe guide supporting a MEMS-type ultra-fine square probe in inspection equipment for ultra-high-speed, high-integration system semiconductors. Therefore, when the silicon nitride substrate material was manufactured by applying the characteristic powder composition and mixing method of the present invention, the low-cost vacuum atmosphere and pressure precision control molding method, and the relatively low-temperature, low-pressure (near normal pressure) nitrogen atmosphere sintering method, upon observation of the microstructure after thin-plate lapping, a dense microstructure with low defects (low pores: 1 or less pore defects with a diameter of 30 μm or more) was confirmed, and when processing an ultra-fine laser square hole of □32*32 μm, pitch 8 μm, the square hole tolerance was within 1 μm, the corner R was within 4 μm, the square hole straightness (the degree of unevenness of the square hole) was within 1 μm, and the square hole taper (the difference between the incident and exit square holes) was It was confirmed that it was neatly processed to within 2~3μm.

Hereinafter, in order to help understand the present invention, examples and the like will be described in detail. However, the examples according to the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited to the following examples. The examples of the present invention are provided to more completely explain the present invention to a person having average knowledge in the art.

<Example 1>

After mixing each powder into four types of mixing compositions, the substrates were formed using low-cost vacuum and pressure precision control press forming equipment, and temperature-dependent sintering experiments were conducted in a relatively low-temperature, low-pressure (near normal pressure) atmosphere sintering furnace.

The density (g/cm3) of the silicon nitride substrate according to the mixing composition and sintering temperature of the four types of powders according to the present invention is shown in Table 1 below, and the number (ea) of defects (pores with a diameter of 30 μm or more) of the silicon nitride substrate according to the powder mixing composition and sintering temperature is as shown in Table 2 below.

No Powder mixing composition Sintering temperature (°C) 1650 1725 1800 1 Silicon nitride/alumina/yttria 2.95 3.17 3.16 2 Silicon nitride/alumina/yttria/titanium oxide 3.02 3.15 3.18 3 Silicon nitride/alumina/yttria/titanium oxide
/magnesium oxide 3.09 3.23 3.21 4 Silicon nitride/alumina/yttria/titanium oxide
/Magnesium oxide/Silicon oxide 3.11 3.22 3.20

No Powder mixing composition Sintering temperature (°C) 1725 1800 1 Silicon nitride/alumina/yttria 6 8 2 Silicon nitride/alumina/yttria/titanium oxide 13 17 3 Silicon nitride/alumina/yttria/titanium oxide
/magnesium oxide 0 2 4 Silicon nitride/alumina/yttria/titanium oxide
/Magnesium oxide/Silicon oxide 1 3

<Example 2>

For the four types of mixing compositions mentioned above, the density of the silicon nitride ceramic substrate material was measured after sintering at relatively low temperatures of 1650 to 1800 ℃, and the number of defects, i.e., pores with a diameter of 30 μm or more, were measured using a three-dimensional vision measuring device on the entire surface of a 100*100 substrate. In addition, Fig. 2 shows comparative microstructure photographs of the substrate surface examined using a three-dimensional vision measuring device at a magnification of 94.2 times for each mixing composition and sintering temperature. Here, it can be seen that Composition 3 is the optimal powder mixing composition that enables the manufacture of a high-density, low-defect silicon nitride substrate at a sintering temperature of 1725 ℃. However, composition No. 4 satisfies the density and microstructure standards of silicon nitride for typical system semiconductor inspection equipment with a density of 3.2 g/cm3 or more and low defects (low pores: 1 or less with a diameter of 30 μm or more), and when it includes silicon oxide, the sintering temperature can be lowered, thereby providing the effect of reducing process costs, which is one of the purposes of the present invention.

Figure 2 is a comparative photograph of the microstructure of the substrate surface according to the mixing composition and sintering temperature.

<Example 3>

The heat treatment process was performed at 1300 to 1500°C for 2 to 5 hours using a heat treatment jig processed to a flatness of 0.01 mm or less in a nitrogen atmosphere after vacuum heat treatment, while applying a load of 3 kg or more. After that, a 3D vision measuring device was used to measure the z-axis step from the floor at 5 points on a 100*100 substrate, and the TTV (flatness) and the presence of bending defects were determined by measuring whether the maximum and minimum difference was less than 40 μm (+/- 0.02 mm). Table 3 shows the TTV (flatness) measurement values according to the heat treatment temperature and time conditions.

Fig. 3 shows a photograph of the degree of substrate bending according to the measurement position and the range of TTV (flatness) measurement values in a 100*100 silicon nitride substrate. It was confirmed that the TTV (flatness) value was less than 30μm and there was no bending defect when heat-treated at 1400℃ for 4 to 6 hours. Fig. 3 shows an example of the degree of substrate bending according to the measurement position and the range of TTV (flatness) measurement values in a 100*100 silicon nitride substrate.

Heat treatment
condition Heat treatment
best
Temperature (°C) Heat treatment
maintain
hour
(hr) (G) ① ② ③ ④ ⑤ TTV
(flatness) (mm) (mm) (mm) (mm) (mm) (mm) (mm) #1 1300 2 0.599 0.167 0.116 0.170 0.144 0.135 0.098 #2 1300 4 0.584 0.246 0.231 0.230 0.231 0.231 0.083 #3 1300 6 0.573 0.319 0.302 0.311 0.349 0.320 0.048 #4 1400 2 0.589 0.182 0.216 0.196 0.233 0.228 0.066 #5 1400 4 0.591 0.321 0.325 0.315 0.339 0.333 0.029 #6 1400 6 0.585 0.312 0.291 0.312 0.318 0.319 0.030 #7 1500 2 0.586 0.299 0.309 0.347 0.347 0.331 0.051 #8 1500 4 0.591 0.334 0.347 0.324 0.357 0.378 0.054 #9 1500 6 *White discoloration and stains (trace of reaction and adhesion falling off) were found at 1500℃ for 4 hours, so no further processing was performed.

<Example 4>

The low-cost, high-quality black densified (high-density, low-pore) silicon nitride substrate developed in the present invention is applied as a probe guide supporting a MEMS-type ultra-fine square probe in inspection equipment for ultra-high-speed, high-integration system semiconductors. Therefore, finally, the ultra-fine laser square hole machinability was verified using laser drilling equipment that is optimal for ultra-fine laser square hole machining of the silicon nitride substrate.

Figure 4 shows a photo of the microstructure and ultrafine laser square hole (□0.032 mm (32 μm), pitch 0.008 mm (8 μm)) processing verification after thin-plate lapping processing (100*100*0.25 mm) of a low-cost, high-quality black densified silicon nitride substrate material for system semiconductor measuring equipment developed in the present invention. As can be seen here, when observing the microstructure after thin-plate lapping of the silicon nitride substrate material manufactured by applying the characteristic compounded powder composition and mixing method of the present invention, the low-cost vacuum atmosphere and pressure precision control molding method, and the relatively low-temperature and low-pressure (near normal pressure) nitrogen atmosphere sintering method, a dense microstructure with low defects (low pores: 1 or less pores with a diameter of 30 μm or more) was confirmed, and when processing an ultra-fine laser square hole of □32*32 μm, pitch 8 μm, it was confirmed that the square hole tolerance was within 1 μm, the corner R was within 4 μm, the square hole straightness (the degree of unevenness of the square hole) was within 1 μm, and the square hole Taper (the difference between the incident and exit square holes) was within 2 to 3 μm, so that it was cleanly processed.

While the specific parts of the present invention have been described in detail above, it is obvious to those skilled in the art that such specific descriptions are merely preferred embodiments and that the scope of the present invention is not limited thereto. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (8)

A mixed powder for a silicon nitride ceramic substrate manufactured by adding 71 to 95 wt% of silicon nitride powder, 1 to 5 wt% of alumina, 1 to 5 wt% of yttria, 1 to 5 wt% of magnesium oxide, and 1 to 7 wt% of titanium oxide in a weight ratio of 1:4:2 to isopropyl alcohol and mixing silicon nitride balls for 24 to 96 hours at a ball mill rotation speed of 30 to 50 RPM, drying, and then filtering through a 100 to 150 μm sieve.
In the first paragraph,
The above-mentioned mixed powder is a mixed powder for a silicon nitride ceramic substrate further containing 1 to 7 wt% of silicon oxide.
(S1) A step for producing a compound powder containing 71 to 95 wt% of silicon nitride powder, 1 to 5 wt% of alumina, 1 to 5 wt% of yttria, 1 to 5 wt% of magnesium oxide, and 1 to 7 wt% of titanium oxide;
(S2) A step of mixing the above mixed powder: isopropyl alcohol: silicon nitride balls in a weight ratio of 1:4:2, mixing at a ball mill rotation speed of 30 to 50 RPM for 24 to 96 hours, and then drying to obtain a uniform mixed powder;
(S3) A step of forming a molded body using the above mixed powder using a vacuum atmosphere precision pressure control molding equipment under the conditions of a pressure cycle of 50 MPa to 125 MPa per unit area, increasing the pressure for 1 to 5 minutes, maintaining the highest pressure for 3 to 8 minutes, and reducing the pressure for 1 to 5 minutes; and
(S4) A step of sintering the above-mentioned molded body in a nitrogen atmosphere sintering furnace at a low pressure of 800 torr (1.1 bar) at 1700 to 1750°C for 4 to 7 hours to obtain a silicon nitride substrate;
A method for manufacturing a silicon nitride substrate for a system semiconductor inspection equipment including a .
In the third paragraph,
A method for manufacturing a silicon nitride substrate for system semiconductor inspection equipment, wherein the above-mentioned compounded powder further contains 1 to 7 wt% of silicon oxide.
A silicon nitride substrate for a system semiconductor inspection device manufactured by the method of claim 3 or 4.
In paragraph 5,
A silicon nitride substrate for system semiconductor inspection equipment, characterized in that the silicon nitride substrate has a density of 3.2 g/cm ³ or more and has 1 or less pores having a diameter of 30 μm or more.
A method for controlling bending of a silicon nitride substrate, which significantly eliminates bending defects during thin plate polishing, to obtain flatness of a silicon nitride substrate for use as a probe guide for system semiconductor inspection equipment using a silicon nitride substrate according to Article 5.
In Article 7,
A method for controlling bending of a silicon nitride substrate, characterized in that the heat treatment method comprises heat treating a silicon nitride substrate that has undergone bending due to processing stress during thin plate polishing at 1400°C for 4 to 6 hours using a heat treatment jig that has been processed to a flatness of 0.01 mm or less in a heat treatment furnace under a vacuum and nitrogen atmosphere, while applying a load of 3 kg or more.