JP2018093184A - Semiconductor device and semiconductor device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a high-resistance region capable of withstanding a heat treatment at a temperature equal to or higher than 200°C.SOLUTION: A manufacturing method of a semiconductor device 10 comprises the steps of: irradiating a p type semiconductor substrate 12 where a semiconductor element is formed with hydrogen(H) ion to form a high resistance region 30 which is a region with a hydrogen density of not less than 2×10cmand not more than 2×10cmand has a resistivity higher than that of the p type semiconductor substrate 12 before ion irradiation; and heating at a temperature not less than 200°C and not more than 400°C, the p type semiconductor substrate 12 where the high resistance region 30 is formed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a semiconductor device and a method for manufacturing the semiconductor device.

  In recent years, CMOS technology has improved, and SoC (System on a Chip) in which an analog circuit and a digital circuit are mixedly mounted is used for various applications. In such a hybrid chip, a high resistance region is formed in the semiconductor substrate in order to improve the characteristics of the analog circuit. For example, a high resistance region for noise reduction is formed by performing ion irradiation a plurality of times while changing acceleration energy from the back side of the element region (see, for example, Patent Document 1).

JP2015-1119039A

  In the above-mentioned document, it is reported that when a heat treatment at 200 ° C. or higher is applied to a high resistance region formed by ion irradiation, a remarkable decrease in resistivity occurs, and for the purpose of stabilizing the resistivity, 200 ° C. or lower is reported. It describes that it is desirable to add heat treatment. However, in the manufacturing process of the semiconductor device, a post process involving a heat treatment at 200 ° C. or higher may be performed, and in that case, the high resistivity obtained by ion irradiation cannot be maintained.

  An exemplary object of an embodiment of the present invention is to provide a technique for forming a high resistance region that can withstand heat treatment at 200 ° C. or higher.

In a method for manufacturing a semiconductor device according to an embodiment of the present invention, a hydrogen (H) ion is irradiated to a p-type semiconductor substrate on which a semiconductor element is formed, and a hydrogen density is 2 × 10 ¹⁵ cm ⁻³ or more and 2 × 10 ¹⁷ cm ^{−. 3} and that the following become a region to form a high resistance region is higher resistivity than the p-type semiconductor substrate before ion irradiation, high-resistance region is formed a p-type semiconductor substrate 400 ° C. below 200 ° C. or higher Heating at a temperature.

Another embodiment of the present invention is a semiconductor device. This apparatus includes a p-type semiconductor substrate, a semiconductor element provided on the p-type semiconductor substrate, and a high resistance region provided in the p-type semiconductor substrate. The high resistance region is a region where the hydrogen density is 2 × 10 ¹⁵ cm ⁻³ or more and 2 × 10 ¹⁷ cm ⁻³ or less and has a higher resistivity than the p-type semiconductor substrate.

  Note that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention replaced with each other among methods, apparatuses, systems, and the like are also effective as an aspect of the present invention.

  According to the present invention, a high resistance region that can withstand heat treatment at 200 ° C. or higher can be formed.

It is sectional drawing which shows typically the structure of the semiconductor device which concerns on embodiment. It is a graph which shows an example of the resistivity change by helium (He) ion irradiation and heat processing which concern on a comparative example. It is a graph which shows an example of the resistivity change by hydrogen (H) ion irradiation and heat processing which concern on an Example. It is a graph which shows an example of the resistivity change by hydrogen (H) ion irradiation and heat processing which concern on another Example. It is a graph which shows the activation rate of hydrogen by heat processing. It is a graph which shows typically carrier concentration change by heat processing. It is a graph which shows an example of the relationship between the hydrogen density and the resistivity change by heat processing. It is a graph which shows an example of the relationship between the dose of hydrogen ion irradiation, and hydrogen density. 3 is a flowchart schematically showing a method for manufacturing a semiconductor device.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. In addition, the structure described below is an illustration and does not limit the scope of the present invention at all. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. In each cross-sectional view referred to in the following description, the thickness and size of the semiconductor substrate and other layers are for convenience of description, and do not necessarily indicate actual dimensions and ratios.

  FIG. 1 is a cross-sectional view schematically showing the structure of a semiconductor device 10 according to an embodiment. The semiconductor device 10 is an integrated circuit (IC) such as a system LSI or a system-on-chip. The semiconductor device 10 includes a semiconductor substrate 12 and a wiring layer 18.

The semiconductor substrate 12 is a low-resistance semiconductor substrate having a resistivity of 100 Ω · cm or less, and is a semiconductor substrate having a resistivity of about 1 to 100 Ω · cm. The semiconductor substrate 12 is, for example, a p-type silicon (Si) wafer manufactured by the Czochralski (CZ) method. A wafer manufactured by the CZ method has a lower resistivity and is less expensive than a high resistance wafer manufactured by a floating zone (FZ) method or the like. In one embodiment, the resistivity of the semiconductor substrate 12 is 4 Ω · cm and the p-type carrier concentration is 3.4 × 10 ¹⁵ cm ⁻³ .

  A first element region 22 and a second element region 24 are provided on the main surface 14 of the semiconductor substrate 12. For example, a first semiconductor element 26 for a digital circuit is provided in the first element region 22, and a second semiconductor element 28 for an analog circuit is provided in the second element region 24. The first semiconductor element 26 and the second semiconductor element 28 are, for example, a transistor or a diode. Each of the first element region 22 and the second element region 24 is provided with an impurity diffusion layer such as a well region, a source / drain region, and a contact region for forming a semiconductor element.

  In this specification, a direction orthogonal to the main surface 14 of the semiconductor substrate 12 may be referred to as a vertical direction or a depth direction. In the semiconductor substrate 12, the direction toward the main surface 14 may be referred to as an upward direction or the upper side, and the direction toward the back surface 16 opposite to the main surface 14 may be referred to as a downward direction or a lower side. In addition, a direction parallel to the main surface 14 may be referred to as a horizontal direction or a horizontal direction.

  A high resistance region 30 is provided inside the semiconductor substrate 12. The high resistance region 30 is a region having a higher resistivity than the body portion of the semiconductor substrate 12. The high resistance region 30 has a resistivity of 100 Ω · cm or more, for example, a resistivity of 500 Ω · cm or more, and preferably 1 kΩ · cm or more. The high resistance region 30 includes a trench type high resistance region 32 and a planar type high resistance region 34.

  The trench type high resistance region 32 is provided in the isolation region 20 between the first element region 22 and the second element region 24 and has a certain depth from the main surface 14 to the back surface 16 of the semiconductor substrate 12. It is formed. The depth of the trench type high resistance region 32 is 20 μm or more, preferably about 50 μm to 200 μm. The trench type high resistance region 32 is formed so as to reach a position deeper than the impurity diffusion layer formed in the first element region 22 and the second element region 24. The trench type high resistance region 32 has a function of improving the characteristics of the analog circuit by blocking noise from the digital circuit toward the analog circuit, for example.

  The planar high resistance region 34 extends in the horizontal direction in the second element region 24. The planar type high resistance region 34 may be provided so as to extend in the horizontal direction from the isolation region 20 to the second element region 24 and form a high resistance region continuous with the trench type high resistance region 32. The planar high resistance region 34 is formed immediately below the analog circuit, thereby contributing to improvement of the characteristics of the analog circuit.

  In the illustrated example, both the trench type high resistance region 32 and the planar type high resistance region 34 are formed inside the semiconductor substrate 12, but in the modification, the trench type high resistance region 32 and the planar type high resistance region 34 are formed. Only one of 34 may be provided.

  The high resistance region 30 is formed by irradiating the body portion of the semiconductor substrate 12 that is a low resistance substrate with hydrogen (H) ions. When the wafer is irradiated with ions, the ions reach a depth corresponding to the acceleration energy of the ions. At that time, lattice defects are formed in the vicinity including the reached region, and the regularity (periodicity) of the crystal is disturbed. In such a region with many lattice defects, carriers (electrons or holes) are easily scattered, and the movement of carriers is hindered. As a result, in a region where local lattice defects are generated by ion irradiation, the resistivity is increased as compared to before irradiation.

  The position and range in the depth direction where the resistivity is increased by ion irradiation can be adjusted by appropriately selecting the acceleration energy and irradiation amount of ion irradiation. For example, the depth position where the high resistance region is formed can be adjusted by adjusting the acceleration energy of ions when ion irradiation is performed. Further, by selecting the acceleration energy of ion irradiation, the depth position where the high resistance region is formed, the range in the depth direction (half-value width), and the lateral spread width can be adjusted. Furthermore, a thicker high resistance region can be formed in the depth direction by performing ion irradiation a plurality of times while changing the acceleration energy.

In this embodiment mode, hydrogen (H) ions are irradiated with acceleration energy of 1 MeV or more and 100 MeV or less. For example, monovalent hydrogen ions ( ¹ H ⁺ ) are irradiated with acceleration energy of 4 MeV, 8 MeV, and 17 MeV. As an apparatus for irradiating an ion beam with such acceleration energy, a cyclotron system or a bandegraph system is used. By using such irradiation conditions, ions can reach the position of a depth of 100 μm or more from the vicinity of the main surface 14 of the semiconductor substrate 12 in the silicon wafer.

The resistivity of the high resistance region formed by ion irradiation depends on the density (defect density) of the generated lattice defects. According to the knowledge of the present inventors, it is known that if the defect density is 1 × 10 ¹⁷ cm ⁻³ or more, a resistivity of 1 kΩ · cm or more can be suitably obtained. Such a defect density can be realized by setting the irradiation amount (dose amount) of hydrogen ions to 1 × 10 ¹³ cm ⁻² or more when the acceleration energy of irradiation ions is 4 MeV to 17 MeV.

  It is known that the resistivity of the high resistance region formed in this way is lowered by applying heat treatment. According to the knowledge of the inventors, a decrease in resistivity is observed by heating the semiconductor substrate 12 after ion irradiation to 200 ° C. or higher, and when the semiconductor substrate 12 is heated to 300 ° C. or higher or 400 ° C. or higher, the resistivity is reduced. Remarkably reduced. This is considered to be because lattice defects are recovered by heat treatment and the defect density is lowered. Therefore, when a high resistance region is formed by ion irradiation, it may be preferable not to apply heat treatment at 200 ° C. or higher in the subsequent steps.

  On the other hand, in order to form the high resistance region 30 at the target positions such as the isolation region 20 and the second element region 24, ion irradiation is performed before dicing the wafer, that is, at a stage before the post-process in the semiconductor process. Need to run. In post processes, heat treatments such as die bonding, wire bonding, and resin sealing are performed. In these processes, the semiconductor substrate 12 can be heated to a temperature of about 200 ° C. to 300 ° C. For this reason, the resistivity of the high resistance region is lowered by the heat treatment in the subsequent process, and a desired resistivity (for example, 500 Ω · cm or more) may not be maintained.

  Therefore, in this embodiment, hydrogen implanted into the semiconductor substrate 12 by ion irradiation is activated by heat treatment so that the resistivity of the high resistance region is maintained even after the heat treatment. When hydrogen is activated by heat treatment, the n-type carrier concentration increases due to donor formation, so that majority carriers (p-type carriers) of the semiconductor substrate 12 which is p-type are neutralized and the conductivity is lowered. For example, by activating hydrogen, an n-type carrier concentration comparable to the p-type carrier concentration of the semiconductor substrate 12 can be obtained, so that the semiconductor substrate 12 can be neutralized and the resistivity can be increased.

FIG. 2 is a graph showing an example of resistivity change due to helium (He) ion irradiation and heat treatment according to a comparative example. In the comparative example, helium ions ( ³ He ²⁺ ) are used instead of hydrogen ions ( ¹ H ⁺ ). The acceleration energy is 23 MeV, the dose is 1.0 × 10 ¹³ cm ⁻² , and the irradiation target is a p-type silicon substrate of about 4 Ω · cm. FIG. 2 shows the resistivity distribution in the depth direction of the substrate before ion irradiation, after ion irradiation (before heat treatment) and after heat treatment (200 ° C., 250 ° C., 300 ° C.). As shown in the figure, a high resistance region of about 1 to 2 kΩ · cm can be formed up to a depth of about 60 μm before the heat treatment, and a high resistance region having almost the same resistivity distribution can be maintained even after the heat treatment at 200 ° C. ing. However, after the heat treatment at 250 ° C., the resistivity of the high resistance region is less than 1 kΩ · cm, partially less than 500 Ω · cm, and after the heat treatment at 300 ° C., the resistivity of the high resistance region is 100 Ω · cm. Is less than In this way, when ion irradiation is performed using helium, it is understood that the resistivity in the high resistance region is lowered by the heat treatment exceeding 200 ° C., and the resistivity is remarkably lowered by the heat treatment at 300 ° C. or higher.

FIG. 3 is a graph showing an example of resistivity change by hydrogen (H) ion irradiation and heat treatment according to the example. In this example, hydrogen ions ( ¹ H ⁺ ) are irradiated, the acceleration energy is 8 MeV, the dose is 1.0 × 10 ¹⁴ cm ⁻² , and the irradiation target is a p-type of about 4 Ω · cm. It is a silicon substrate. FIG. 3 shows the resistivity distribution in the depth direction of the substrate before ion irradiation, after ion irradiation (before heat treatment) and after heat treatment (250 ° C., 400 ° C.). As shown in the figure, a high resistance region of 1 kΩ · cm or more can be formed up to a depth of about 110 μm before the heat treatment, and a high resistance region having substantially the same resistivity distribution can be maintained even after the heat treatment at 250 ° C. . Further, even after the heat treatment at 400 ° C., a high resistance region of 1 kΩ · cm or more can be maintained at a depth of 10 μm to 80 μm. In this way, by using hydrogen ions, a high resistance region of 500 Ω · cm or more, preferably 1 kΩ · cm or more can be maintained even when heat treatment exceeding 200 ° C. or heat treatment exceeding 300 ° C. is applied.

FIG. 4 is a graph showing an example of resistivity change by hydrogen (H) ion irradiation and heat treatment according to another embodiment. In the present embodiment, hydrogen ions ( ¹ H ⁺ ) are irradiated as in FIG. 3, the acceleration energy is 8 MeV, and the irradiation target is a p-type silicon substrate of about 4 Ω · cm. In this embodiment, a dose amount different from that in FIG. 3 is used, and the dose amount is 2.6 × 10 ⁻¹⁴ cm ⁻² , which is higher than that in the above-described embodiment. FIG. 4 shows the resistivity distribution in the depth direction of the substrate before ion irradiation, after ion irradiation (before heat treatment) and after heat treatment (200 ° C., 300 ° C., 400 ° C.). As shown in the figure, a high resistance region of 1 kΩ · cm or more can be formed to a depth of about 45 μm before the heat treatment, and a high resistance region having substantially the same resistivity distribution can be maintained even after the heat treatment at 200 ° C. . However, after heat treatment at 300 ° C., the resistivity at a depth of about 10 to 30 μm is less than 1 kΩ · cm, and after heat treatment at 400 ° C., it is less than 100 Ω · cm. This is because, by increasing the dose amount of hydrogen ions, hydrogen is excessively donored, the conductivity type is reversed from p-type to n-type, and the resistivity decreases due to the increase of the n-type carrier concentration which has become majority carriers. The cause is thought to be.

  From the above comparative examples and examples, in order to maintain a high resistivity (500 Ω · cm or more) even after a heat treatment exceeding 200 ° C., it is necessary to appropriately control the dose amount of hydrogen ions and the temperature of the heat treatment. It can be said.

  FIG. 5 is a graph showing the activation rate of hydrogen by heat treatment, and shows the relationship between temperature and activation rate. As shown in the drawing, in the range of 200 ° C. to 400 ° C., the activation rate of hydrogen is low, and the increase in the activation rate due to temperature rise is also gradual. On the other hand, when the temperature exceeds 400 ° C., the increase rate of the activation rate due to the temperature rise increases, and the value of the activation rate also exceeds 10%. Therefore, by using a heat treatment in the range of 200 ° C. to 400 ° C. where the increase in the activation rate due to the temperature rise is moderate, even if individual differences occur in the temperature of the heat treatment in the subsequent process, resistance due to the difference in the treatment temperature A significant change in rate can be suppressed.

FIG. 6 is a graph schematically showing changes in carrier concentration due to heat treatment, and schematically shows values of n-type carrier concentration converted into donors by heat treatment for three different hydrogen densities. A has a hydrogen density of 5 × 10 ¹⁶ cm ⁻³ and corresponds to the example of FIG. 3 (energy: 8 MeV, dose: 1.0 × 10 ¹⁴ cm ⁻² ). B has a hydrogen density of 1.3 × 10 ¹⁷ cm ⁻³ and corresponds to the example of FIG. 4 (energy: 8 MeV, dose: 2.6 × 10 ¹⁴ cm ⁻² ). C has a hydrogen density of 5 × 10 ¹⁵ cm ⁻³ , and D has a hydrogen density of 2.5 × 10 ¹⁶ cm ⁻³ . The broken line in the graph indicates the p-type carrier concentration in the semiconductor substrate and is 3.4 × 10 ¹⁵ cm ⁻³ .

In the case of A, the n-type carrier concentration is about 1.0 × 10 ¹⁵ cm ^{−3 at} 200 ° C., and is about 3.4 × 10 ¹⁵ cm ^{−3 the} same as the p-type carrier concentration of the substrate at about 330 ° C., and 400 ° C. In this case, it becomes about 6.0 × 10 ¹⁵ cm ⁻³ . As a result, the p-type carrier concentration and n-type carrier concentration are approximately the same in the range of 250 ° C to 400 ° C where the decrease in resistivity due to the recovery of lattice defects becomes significant, and high resistivity is achieved by neutralizing the substrate. it can. As a result, as shown in FIG. 3, even if heat treatment at 200 ° C. to 400 ° C. is applied, a high resistance of 1 kΩ · cm or more can be maintained.

In the case of B, the n-type carrier concentration is about 2.6 × 10 ¹⁵ cm ^{−3 at} 200 ° C., and is about 3.4 × 10 ¹⁵ cm ⁻³ which is the same as the p-type carrier concentration of the substrate at about 230 ° C. About 6.8 × 10 ¹⁵ cm ^−3, which is twice the p-type carrier concentration of the substrate, and 1.0 × 10 ¹⁶ cm ⁻³ or more at 350 ° C. or higher. As a result, as shown in FIG. 4, when the heat treatment at 300 ° C. or higher is performed, the resistivity is decreased by n-type inversion of the substrate, and when the heat treatment at 400 ° C. is performed, the resistivity of the substrate is further decreased.

In the case of C, since the hydrogen density is 0.1 times that of A, the carrier concentration due to hydrogen donor formation is small, and the p-type carrier concentration (3.4 × 10 4) of the substrate even when heat treatment at 400 ° C. or higher is applied. ¹⁵ cm ⁻³ ). As a result, even if heat treatment at 200 ° C. to 400 ° C. is applied, neutralization of the substrate does not occur, and it is considered that only a decrease in resistivity due to a decrease in defect density occurs. Similarly, in the case of D, the hydrogen density is 0.5 times that of A and does not reach the p-type carrier concentration (3.4 × 10 ¹⁵ cm ⁻³ ) of the substrate even when heat treatment at 200 ° C. to 400 ° C. is applied. Therefore, it is considered that the neutralization of the substrate does not occur, and only the resistivity decreases due to the decrease in defect density.

FIG. 7 is a graph showing an example of the relationship between the hydrogen density and the resistivity change due to the heat treatment, and shows the resistivity change corresponding to the conditions A, B, C, and D in FIG. As illustrated, in the case of A (hydrogen density: 5 × 10 ¹⁶ cm ⁻³ ), a high resistance of 1 kΩ · cm or more can be maintained in the range of 200 ° C. to 400 ° C. In the case of B (hydrogen density: 1.3 × 10 ¹⁷ cm ⁻³ ), a high resistance of 500 Ω · cm or more can be maintained in the range of 200 ° C. to 300 ° C., but the resistivity becomes 200 Ω · cm or less at 350 ° C. or more. turn into. In the case of C (hydrogen density: 5 × 10 ¹⁵ cm ⁻³ ), a high resistance of 1 kΩ · cm can be maintained by the heat treatment at 200 ° C., but when the heat treatment exceeds 200 ° C., the resistivity is remarkably reduced to 250 ° C. After the above heat treatment, it becomes 10 Ω · cm or less. This is thought to be because the n-type carrier concentration for neutralization is insufficient because the hydrogen density is low. In the case of D (hydrogen density: 2.5 × 10 ¹⁶ cm ⁻³ ), a high resistance of 500 Ω · cm or more can be maintained in the range of 200 ° C. to 230 ° C., but the resistivity is 200 Ω · cm at 250 ° C. or more. It becomes the following.

From the above consideration, in order to maintain a high resistivity even after the heat treatment, it is necessary to realize an n-type carrier concentration comparable to the p-type carrier concentration of the semiconductor substrate 12 in the temperature range of 200 ° C. to 400 ° C. is there. Since the hydrogen activation rate by heat treatment at 200 ° C. to 400 ° C. is about 2% to 10%, a hydrogen density of about 10 to 50 times the p-type carrier concentration of the semiconductor substrate 12 may be realized. In general, since the p-type carrier concentration of a p-type silicon substrate having a low resistance (1 to 100 Ω · cm) is 10 ¹⁴ to 10 ¹⁶ cm ⁻³ , 5 × 10 ¹⁵ cm ^{−3 to} 2 × 10 ⁻¹⁷ cm ^It is only necessary to realize a hydrogen density of ⁻³ or less. For example, when the p-type carrier concentration is 3.4 × 10 ¹⁵ cm ⁻³ , a hydrogen density of 3.4 × 10 ¹⁶ cm ⁻³ or more and 1.7 × 10 ⁻¹⁷ cm ⁻³ or less is preferable.

  If the conductivity type of at least a part of the high resistance region 30 is inverted to the n type, a pn junction is formed in the high resistance region, which may affect the operation of the circuit elements formed on the semiconductor substrate 12. In order to suppress such an influence, the hydrogen density value may be controlled so that the n-type carrier concentration due to the activation of hydrogen does not exceed the p-type carrier concentration of the semiconductor substrate 12. That is, the hydrogen density and the heat treatment temperature may be controlled so that the conductivity type of the high resistance region 30 remains p-type.

FIG. 8 is a graph showing an example of the relationship between the dose of hydrogen ion irradiation and the hydrogen density, and shows the case where the acceleration energy of hydrogen ions is 4 MeV, 8 MeV, and 17 MeV. As shown in the figure, the dose amount of hydrogen ions and the hydrogen density after irradiation are in a proportional relationship. Also, the lower the irradiation energy, the higher the hydrogen density that can be obtained. This is because if the acceleration energy is low, the range in the depth direction in which hydrogen ions are implanted is limited, and the amount of hydrogen implantation per unit volume increases. From the graph, in order to realize a hydrogen density of 5 × 10 ¹⁵ cm ⁻³ or more and 2 × 10 ⁻¹⁷ cm ⁻³ or less, in the case of 4 MeV, 1 × 10 ⁻¹³ cm ⁻² or more and 2 × 10 ⁻¹⁴ cm ^{− 2} or less, 1 × 10 ⁻¹³ cm ⁻² or more and 4 × 10 ⁻¹⁴ cm ⁻² or less in the case of 8 MeV, 3.6 × 10 ⁻¹³ cm ⁻² or more and 1 × 10 ⁻¹⁵ cm ⁻² or less in the case of 17 MeV You can do it. Note that if ion irradiation is performed with these doses, a defect density of 1 × 10 ¹⁷ cm ⁻³ or more can be obtained, so that a high resistivity of 500 Ω · cm or more can be realized even before the heat treatment.

  Next, a method for manufacturing the semiconductor device 10 according to the present embodiment will be described. FIG. 9 is a flowchart schematically showing a method for manufacturing the semiconductor device 10. First, an element is formed on the p-type semiconductor substrate 12 by various processes (S10), a wiring layer is formed on the semiconductor substrate 12, and a protective film for protecting the formed element and wiring is formed (S14). ). Steps S10 to S14 are steps referred to as “previous steps” in the semiconductor process, and high-temperature treatment at 400 ° C. or higher such as thermal oxidation, thermal diffusion, CVD, and annealing can be performed. Subsequently, the semiconductor substrate 12 is irradiated with hydrogen ions to form the high resistance region 30 (S16), and the backside polishing of the semiconductor substrate 12 is performed (S18). Steps S16 and S18 are so-called “intermediate steps” or “post-passivation processes (PPPs)”.

  Subsequently, a post-process (S20) including heat treatment is performed to complete a semiconductor integrated circuit. In the post-process of S20, for example, a step of dicing the wafer into individual pieces, a die bonding step of bonding the separated chips onto the mounting substrate, a step of connecting the mounting substrate and the chips by wire bonding, The process of sealing with resin is included. For example, in the die bonding step, the wire bonding step, and the resin sealing step, a heat treatment at about 200 ° C. to 300 ° C. is performed, and in a certain example, the maximum temperature of the heat treatment is about 260 ° C. An annealing process for heating the semiconductor device 10 may be performed separately from the bonding and sealing process. In the annealing treatment, the resistivity of the high resistance region 30 may be stabilized by heating the high resistance region 30 at a predetermined temperature of 200 ° C. or more and 400 ° C. or less. It is sufficient that this annealing treatment is performed for a relatively short time of 10 minutes or less, and may be a time of 5 minutes or less, 1 minute or less, or 30 seconds or less.

  The present invention has been described based on the embodiments. It is understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, and various modifications are possible, and such modifications are within the scope of the present invention. It is a place.

  In the above-described embodiment, the high resistance region 30 is formed by irradiation with only hydrogen ions. In the modification, the high resistance region may be formed by combining ion irradiation other than hydrogen. For example, the hydrogen density in the above numerical range may be realized by hydrogen ion irradiation, and the above-described numerical defect density may be realized by irradiating ion species other than hydrogen. In a certain modification, a combination of irradiation with hydrogen ions and helium ions may form a high resistance region that can maintain high resistance (500 Ω · cm or more) even when heat treatment at 200 ° C. or higher is performed.

  DESCRIPTION OF SYMBOLS 10 ... Semiconductor device, 12 ... Semiconductor substrate, 14 ... Main surface, 16 ... Back surface, 18 ... Wiring layer, 20 ... Isolation region, 22 ... 1st element area | region, 24 ... 2nd element area | region, 26 ... 1st semiconductor element, 28 ... second semiconductor element, 30 ... high resistance region, 32 ... trench type high resistance region, 34 ... planar type high resistance region.

Claims (9)

The p-type semiconductor substrate on which the semiconductor element is formed is irradiated with hydrogen (H) ions, and is a region where the hydrogen density is 5 × 10 ¹⁵ cm ⁻³ or more and 2 × 10 ¹⁷ cm ⁻³ or less before the ion irradiation. forming a high resistance region having a higher resistivity than the p-type semiconductor substrate;
Heating the p-type semiconductor substrate on which the high-resistance region is formed at a temperature of 200 ° C. or higher and 400 ° C. or lower. The method of manufacturing a semiconductor device according to claim 1, wherein the high resistance region is formed so that a defect density is 1 × 10 ¹⁷ cm ⁻³ or more.   3. The method of manufacturing a semiconductor device according to claim 1, wherein the p-type semiconductor substrate on which the high resistance region is formed is heated at a temperature of 200 ° C. or more and 300 ° C. or less. The high resistance region is formed by irradiation with hydrogen ions having an irradiation energy of 4 MeV to 17 MeV and a dose of 2 × 10 ¹³ cm ^{−2 to} 2 × 10 ¹⁴ cm ^−2. 4. A method for manufacturing a semiconductor device according to claim 3.   The method for manufacturing a semiconductor device according to claim 1, wherein the heating time is 10 minutes or less.   6. The resistivity of the p-type semiconductor substrate before the ion irradiation is 100 Ωcm or less, and the resistivity of the high resistance region after the heating is 500 Ωcm or more. A method for manufacturing the semiconductor device according to the item.   7. The high resistance region is formed so that the hydrogen density has a value of 10 to 50 times the carrier concentration of the p-type semiconductor substrate before the ion irradiation. A method for manufacturing a semiconductor device according to one item.   The method for manufacturing a semiconductor device according to claim 1, wherein the high-resistance region has a p-type conductivity after the heating. a p-type semiconductor substrate, a semiconductor element provided on the p-type semiconductor substrate, and a high-resistance region provided in the p-type semiconductor substrate,
The high resistance region is a region having a hydrogen density of 5 × 10 ¹⁵ cm ⁻³ or more and 2 × 10 ¹⁷ cm ⁻³ or less and having a higher resistivity than the p-type semiconductor substrate. Semiconductor device.

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