CN105826163A - Preparation method of HRP (High Resistance Poly) resistor and method for changing resistance thereof - Google Patents

Abstract

The present invention proposes a method for preparing HRP resistors and a method for changing their resistance value. The first ion B is implanted into the main body of the resistor, and then the second ion O is implanted. Site B and interstitial O form a B _s O _2i complex that does not affect the resistance value, reducing the carrier concentration of B so that the properties of the resistance can be changed, and the resistance value of the HRP resistance can be changed, and the preparation method is simple and easy OK, good for production. Further, in the proposed method of changing the resistance value of HRP resistance, if the resistance value of HRP resistance is increased, it only needs to be illuminated for a certain time and intensity; if the resistance value of HRP resistance is to be decreased, only a certain temperature The heat treatment can be carried out below.

Description

Preparation method of HRP resistor and method of changing its resistance value

technical field

The invention relates to the field of semiconductor manufacturing, in particular to a method for preparing an HRP resistor and a method for changing its resistance value.

Background technique

In the manufacturing process of a semiconductor chip, in order to realize certain functions of the device, some high-resistance devices, such as HRP (High Resistance Poly, high-resistance polysilicon) resistors, are usually fabricated in the chip. Common preparation methods of HRP resistors in the prior art include the following:

Method 1: directly perform the first ion implantation IMP1 (implanted ions such as B or BF ₂ ) at a specific region of the formed undoped crystalline silicon, and change the resistance value of the crystalline silicon by adjusting the concentration of the implanted ions to achieve the desired value. The required resistance device;

Method 2: Perform the first ion implantation IMP1 in a part of the undoped crystalline silicon, and then perform the second ion implantation IMP2 in another part of the area through the HRP illumination step, and the ion type of the second ion implantation IMP2 It is consistent with the ion type of the first ion implanted into IMP1, but the implanted ion concentration is different, which can also be adjusted;

Method 3: The first ion implantation IMP1 is also performed on a part of the undoped crystalline silicon; and then the second ion implantation IMP2 is performed on another part of the area through the HRP illumination step. The difference is that the second ion implantation IMP2 The ion type is opposite to the ion type of the first ion implanted into IMP1, and it is necessary to ensure that there is a certain difference in the concentration of the implanted ions to avoid incomplete compensation between the two.

However, once the HRP resistor prepared by the above method is completed, its resistance value will be fixed, and it lacks adjustability in some aspects of performance, that is, the application conditions of this fixed high-resistance device are relatively single and strict, and for some different For devices with different resistance values that can realize different functions, it is difficult to use this kind of fixed resistance HRP resistor device, and the value of a device that can easily adjust the resistance can be reflected.

Therefore, it is necessary to propose an HRP resistor with adjustable resistance to meet different functions of the device.

Contents of the invention

The object of the present invention is to provide a preparation method of HRP resistor and a method for changing its resistance value. The resistance value of the prepared HRP resistor can be changed accurately within a certain range, so that the device can meet different functions.

In order to achieve the above object, the present invention proposes a preparation method of HRP resistance, comprising steps:

provide a resistor body;

Performing a first ion implantation on the resistance body, the ion type of the first ion implantation includes B ions;

forming a photoresist on the resistor body, the photoresist exposing part of the resistor body;

Performing a second ion implantation on the exposed resistor body, the ion type of the second ion implantation includes O ions;

A rapid thermal annealing process is performed on the resistor body to form an HRP resistor.

Further, in the method for manufacturing the HRP resistor, B or BF ₂ is used for the first ion implantation.

Further, in the method for manufacturing the HRP resistor, the second ion implantation uses O ₂ .

Further, in the manufacturing method of the HRP resistor, the depth of the second ion implantation is the same as the depth of the first ion implantation.

Further, in the manufacturing method of the HRP resistor, the concentration of the second ion implantation is 1-3 orders of magnitude higher than the concentration of the first ion implantation.

Further, in the manufacturing method of the HRP resistor, the main body of the resistor is crystalline silicon.

Further, in the preparation method of the HRP resistor, the temperature range of the rapid thermal annealing process is 800°C-1200°C, and the annealing time range is 1s-60min.

The present invention also proposes a method for changing the resistance value of the HRP resistance, which is used to change the resistance value of the HRP resistance. The HRP resistance is prepared by the preparation method of the HRP resistance as described in any one of the above, including the steps:

If the resistance value of the HRP resistor is increased, the HRP resistor is irradiated under a predetermined light intensity;

If the resistance value of the HRP resistor is reduced, heat treatment is performed on the HRP resistor at a predetermined temperature.

Further, in the method for changing the resistance value of the HRP resistor, the light intensity range is AM1-AM2.

Further, in the method for changing the resistance value of the HRP resistance, the range of the illumination time is 1 hour to 2 hours.

Further, in the method for changing the resistance value of HRP resistance, the temperature range of the heat treatment is 100°C-250°C.

Further, in the method for changing the resistance value of HRP resistance, the heat treatment time range is 0-20 hours.

Compared with the prior art, the beneficial effects of the present invention are mainly reflected in: implanting the first type of ion B into the resistor body, and then performing the implantation of the second type of ion O, because under certain lighting conditions, the replacement of B and The interstitial O forms a B _s O _2i complex that does not affect the resistance value, reducing the carrier concentration of B so that the properties of the resistance can be changed, and the resistance value of the HRP resistance can be changed. Moreover, the preparation method is simple and easy to facilitate Production.

Further, in the proposed method of changing the resistance value of HRP resistance, if the resistance value of HRP resistance is increased, it only needs to be illuminated for a certain time and intensity; if the resistance value of HRP resistance is to be decreased, only a certain temperature The heat treatment can be carried out below.

Description of drawings

Fig. 1 is the flow chart of the preparation method of HRP resistance in an embodiment of the present invention;

2 to 5 are schematic cross-sectional views of the HRP resistor manufacturing process in an embodiment of the present invention.

detailed description

The preparation method of the HRP resistor of the present invention and the method for changing its resistance value will be described in more detail below in conjunction with the schematic diagram, wherein a preferred embodiment of the present invention is shown, and it should be understood that those skilled in the art can modify the present invention described here, while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as the broad knowledge of those skilled in the art, but not as a limitation of the present invention.

In the interest of clarity, not all features of an actual implementation are described. In the following description, well-known functions and constructions are not described in detail since they would obscure the invention with unnecessary detail. It should be appreciated that in the development of any actual embodiment, numerous implementation details must be worked out to achieve the developer's specific goals, such as changing from one embodiment to another in accordance with system-related or business-related constraints. Additionally, it should be recognized that such a development effort might be complex and time consuming, but would nevertheless be merely a routine undertaking for those skilled in the art.

In the following paragraphs the invention is described more specifically by way of example with reference to the accompanying drawings. Advantages and features of the present invention will be apparent from the following description and claims. It should be noted that all the drawings are in a very simplified form and use imprecise scales, and are only used to facilitate and clearly assist the purpose of illustrating the embodiments of the present invention.

Please refer to Figure 1. In this embodiment, a method for preparing an HRP resistor is proposed, including steps:

S1: provide the main body of the resistor;

S2: performing a first ion implantation on the resistor body, where the ion type of the first ion implantation includes B ions;

S3: forming a photoresist on the resistor body, the photoresist exposing part of the resistor body;

S4: performing a second ion implantation on the exposed resistor body, the ion type of the second ion implantation includes O ions;

S5: performing a rapid thermal annealing process on the resistor main body to form an HRP resistor.

Specifically, please refer to FIG. 2 , in step S1 , the resistor body 10 is crystalline silicon, which can be single crystal silicon or polycrystalline silicon, and can be doped to form resistors with different resistance values.

In step S2 , as shown in FIG. 3 , the first ion implantation is performed on the resistor body 10 , and the first ion implantation uses B or BF ₂ , so that the resistance value of the resistor body 10 can be changed. In this application, different resistance values are mainly obtained by implanting different ion implantation concentrations. For example, if a high-resistance device with an HRP resistance value of 1 kohm is required, the implanted ion concentration B or BF ₂ is generally 8*10 ¹⁴ cm ^-3 ; similarly, when the ion implantation concentration is 2.7*10 ¹⁴ cm ^-3 , the obtained HRP resistance is about 3 kohms. The specific injection concentration can be determined according to different resistance values, and is not limited here.

Referring to FIG. 4 , in step S3 , a photoresist 20 is formed on the resistor body 10 , and the photoresist 20 exposes a part of the resistor body 10 and blocks the part that does not need the second ion implantation. Since the resistors have multiple functions, some need to change the resistance value, while some do not need to change the resistance value, so the photoresist 20 can be used for shielding during the preparation process.

Please refer to FIG. 5, in step S4, a second ion implantation is performed on the exposed resistance body 10, the ion type of the second ion implantation includes O ions; the second ion implantation can use _O2 .

After the second ion implantation is completed, a rapid thermal annealing (RTA) process is generally required to form an HRP resistor, wherein the rapid thermal annealing process can activate the doped impurities. The temperature range of the rapid thermal annealing process is 800°C-1200°C, such as 1000°C, and the annealing time range is 1s-60min, such as 30s.

In this embodiment, the depth of the second ion implantation is the same as the depth of the first ion implantation, which is used to ensure that the O ions can completely react with the B ions, which is beneficial to change the resistance value of the HRP resistor. In addition, preferably, the concentration of the second ion implantation is higher than the concentration of the first ion implantation by 1 to 3 orders of magnitude, which can further effectively change and ensure that O ions can completely react with B ions, which is conducive to changing the HRP The resistance value of the resistor.

In another aspect of this embodiment, a method for changing the resistance value of the HRP resistance is also proposed, which is used to change the resistance value of the HRP resistance. The HRP resistance is prepared by the preparation method of the HRP resistance as described above. , including the steps:

If the resistance value of the HRP resistor is increased, the HRP resistor is irradiated under a predetermined light intensity;

If the resistance value of the HRP resistor is reduced, heat treatment is performed on the HRP resistor at a predetermined temperature.

Specifically, the HRP resistor can be irradiated for 1 hour to 2 hours when the light intensity ranges from AM1 to AM2, for example, 1.5 hours when the light intensity is AM1.5, so as to promote the reaction of B ions and O ions to produce B _s O _2i The complex reduces the concentration of B ions, thereby changing the resistance value of the HRP resistance and increasing the resistance value of the HRP resistance.

On the contrary, if the resistance value of the HRP resistor is reduced, the HRP resistor is heat treated at a temperature of 100°C to 250°C for 0 to 20 hours, for example, the HRP resistor is heat treated at a temperature of 150°C After 10 hours, the formed B _s O _2i complex is decomposed, B ions are released, and the concentration of B ions is increased, thereby reducing the resistance value of the HRP resistor.

It can be seen that the resistance value of the HRP resistor can be changed within a certain range through the above method, which is beneficial for application in devices to realize different functions.

To sum up, in the method for manufacturing HRP resistors and the method for changing its resistance provided by the embodiments of the present invention, the first type of ion B is implanted into the main body of the resistor, and then the second type of ion O is implanted. Under light conditions, the substitution B and the interstitial O form a B _s O _2i complex that does not affect the resistance value, which reduces the carrier concentration of B and can change the nature of the resistance, which in turn can change the resistance value of the HRP resistor, and, The preparation method is simple and easy, and is beneficial to production. Further, in the proposed method of changing the resistance value of HRP resistance, if the resistance value of HRP resistance is increased, it only needs to be illuminated for a certain time and intensity; if the resistance value of HRP resistance is to be decreased, only a certain temperature The heat treatment can be carried out below.

The foregoing are only preferred embodiments of the present invention, and do not limit the present invention in any way. Any person skilled in the technical field, within the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the technical solution of the present invention. The content still belongs to the protection scope of the present invention.

Claims (12)

1. the preparation method of a HRP resistance, it is characterised in that include step:

Resistance body is provided；

Carrying out the first ion implanting on described resistance body, the ionic type of the first ion implanting described includes B ion；

Forming photoresistance on described resistance body, described photoresistance exposes partial ohmic main body；

Carrying out the second ion implanting on the resistance body exposed, the ionic type of described the second ion implanting includes O ion；

Described resistance body is carried out rapid thermal anneal process process, forms HRP resistance.

2. the preparation method of HRP resistance as claimed in claim 1, it is characterised in that the first ion implanting described uses B or BF₂。

3. the preparation method of HRP resistance as claimed in claim 1, it is characterised in that described the second ion implanting uses O₂。

4. the preparation method of HRP resistance as claimed in claim 1, it is characterised in that the degree of depth of described the second ion implanting is identical with the degree of depth of the first ion implanting described.

5. the preparation method of HRP resistance as claimed in claim 4, it is characterised in that the concentration of described the second ion implanting is higher than the concentration 1 of the first ion implanting described～3 orders of magnitude.

6. the preparation method of HRP resistance as claimed in claim 1, it is characterised in that described resistance body is crystalline silicon.

7. the preparation method of HRP resistance as claimed in claim 1, it is characterised in that the temperature range of described rapid thermal anneal process is 800 DEG C～1200 DEG C, and annealing time scope is 1s～60min.

8. the method changing HRP resistance, for changing the resistance of HRP resistance, described HRP resistance uses the preparation method of the HRP resistance as according to any one of claim 1 to 7 to be prepared from, it is characterised in that include step:

If the resistance making described HRP resistance increases, then under predetermined light intensity, irradiate described HRP resistance；

If the resistance making described HRP resistance reduces, the most described HRP resistance is carried out heat treatment.

9. the method changing HRP resistance as claimed in claim 8, it is characterised in that described range of light intensity is AM1～AM2.

10. the method changing HRP resistance as claimed in claim 8, it is characterised in that described light application time scope is 1 hour～2 hours.

11. methods changing HRP resistance as claimed in claim 8, it is characterised in that described heat-treatment temperature range is 100 DEG C～250 DEG C.

12. methods changing HRP resistance as claimed in claim 8, it is characterised in that described heat treatment time scope is 0～20 hour.