KR102521976B1 - doping method of substrate - Google Patents

Abstract

The present invention discloses a method for doping a substrate. The method includes providing a substrate, providing a target material on the substrate, and providing a laser beam to the target material to implant conductive impurities of the target material into the substrate.

Description

Substrate doping method {doping method of substrate}

The present invention relates to a semiconductor manufacturing method, and more particularly, to a substrate doping method for implanting conductive impurities into a substrate.

As general semiconductor doping methods, the ion implantation method and the plasma ion doping method are the most general methods. First, the ion implantation method is a method of accelerating and implanting an impurity gas into a substrate. Next, the plasma ion implantation method is a method of implanting impurity gas ions of electron cyclotron resonance (ECR) plasma into a substrate. However, such an impurity gas may be highly toxic. In addition, high-cost impurity gases may have low productivity.

Another object of the present invention is to provide a substrate doping method capable of implanting conductive impurities in a solid state.

In addition, another object of the present invention is to provide a substrate doping method having high productivity.

The present invention discloses a method for doping a substrate. His method includes providing a substrate; providing a target material on the substrate; and injecting conductive impurities of the target material into the substrate by providing a laser beam to the target material.

A substrate doping method according to an example of the present invention includes providing a substrate; and implanting conductive impurities into the substrate. Here, the implanting of the conductive impurities includes providing a laser beam to a solid target material having the conductive impurities to implant the conductive impurities emitted from the target material into the substrate.

As described above, in the substrate doping method according to embodiments of the present invention, conductive impurities emitted from the target material may be implanted into the substrate by providing a laser beam to the target material in a solid state. A target material in a solid state may have a higher productivity than an expensive impurity gas.

1 is a flow chart showing a substrate doping method according to an example of the present invention.
2 to 4 are cross-sectional views of a substrate process according to the substrate doping method of FIG. 1 .
5A to 5C are diagrams showing depth profiles of conductive impurities according to the dose of the laser beam of FIG. 4 .
6 is a view showing an example of the target material of FIG. 4 .
FIG. 7 is a diagram showing a process of releasing first to fourth conductive impurities according to the movement of the laser beam of FIG. 6 .
8A to 8D are process cross-sectional views showing an example of the substrate doping method of FIGS. 2 to 3 .
9 is a circuit diagram showing a semiconductor device formed by the substrate doping method of FIGS. 8A to 8D.
10 is a flow chart showing a substrate doping method according to an example of the present invention.
11 to 13 are process cross-sectional views of an example of the substrate doping method of FIG. 10 .
14 to 16 are process cross-sectional views of an example of the substrate doping method of FIG. 10 .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in different forms. Rather, the embodiments introduced herein are provided so that the disclosed content will be thorough and complete and the spirit of the present invention will be sufficiently conveyed to those skilled in the art, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

Terms used in this specification are for describing embodiments and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, the terms "comprises" and/or "comprising" mean that a stated component, step, operation and/or device excludes the presence or addition of one or more other components, steps, operations and/or elements. I never do that. Also, in the specification, a laser beam, an electron beam, a width, a wavelength, an optical axis, a phase, an interference, a spot size, and a cross section may be understood as meanings mainly used in the field of optics. Since it is according to a preferred embodiment, reference numerals presented in the order of description are not necessarily limited to the order.

1 shows a substrate doping method according to an example of the present invention. 2 to 4 are cross-sectional views of a substrate 10 according to the substrate doping method of FIG. 1 .

Referring to FIGS. 1 and 2 , a substrate 10 is provided (S10). A mask pattern 20 may be formed on the substrate 10. The substrate 10 includes a doping region 12 ) and a closed region 14. The implantation region 12 may be a region into which conductive impurities (36 in FIG. 4) are implanted. The upper surface of the substrate 10 of the implantation region 12 Silver may be exposed from the mask pattern 20. The blocking region 14 may be a region where the mask pattern 20 is substantially formed. 20) can be shielded.

Referring to FIGS. 1, 3, and 4 , conductive impurities 36 are implanted into the substrate 10 (S20). The implantation of the conductive impurities 36 (S20) includes providing a target 30 on the substrate 10 (S22) and providing a laser beam 42 on the target 30 (S24). can do.

Referring to FIGS. 1 and 3 , the target 30 may be provided on the substrate 10 (S22). The target 30 may be spaced apart from each other on the substrate 10 . The target 30 may include a support part 32 and a first target material 34 . The support part 32 may have a window 33 . A first target material 34 may be disposed within the window 33 . The support part 32 may fix the first target material 34 . For example, the target material 34 may have a solid state unlike impurity gas. The solid state target material 34 may have a higher productivity than costly impurity gas. According to one example, the first target material 34 may be aligned on the implantation area 12 . The first target material 34 may have a thickness of about hundreds to thousands of nm.

Referring to FIGS. 1 and 4 , the laser device 40 may provide the laser beam 42 onto the target 30 (S24). For example, the laser device 40 may include a femtosecond high power laser device or a picosecond high power laser device. The first target material 34 may emit electrons 35 and conductive impurities 36 between the target 30 and the substrate 10 . The conductive impurities 36 may break the binding force between molecules or atoms of the first target material 34 and may be provided to the substrate 10 . Conductive impurity 36 may be accelerated into substrate 10 of electrons 35 . This can be explained by the Target-Normal Acceleration model. The conductive impurity 36 may have a positive charge.

5A to 5C show the depth profile of the conductive dopant 36 according to the dose of the laser beam 42 of FIG. 4 .

Referring to FIGS. 4 and 5A , when the dose of the laser beam 42 is constant, the conductive impurities 36 may be implanted at a constant concentration from the surface of the substrate 10 to a certain depth. For example, conductive dopant 36 may have a flat profile 16 .

Referring to FIGS. 4 and 5B , when the dose of the laser beam 42 is gradually decreased, the concentration of the conductive impurities 36 may gradually decrease from the surface of the substrate 10 to a certain depth. In contrast, when the dose of the laser beam 42 is gradually increased, the concentration of the conductive impurities 36 may gradually increase from the surface of the substrate 10 to a certain depth. For example, the conductive dopant 36 may have an obliquely inclined profile 17 .

Referring to FIGS. 4 and 5C , when the laser beam 42 has a high dose and is provided within a short period of time, the conductive impurities 36 may be implanted at a high concentration into a predetermined depth of the substrate 10 . For example, conductive dopant 36 may have a peak profile 18 .

FIG. 6 shows an example of the first target material 34 of FIG. 4 .

Referring to FIG. 6 , the first target material 34 may be formed into a plurality of regions for each type of conductive impurity 36 . According to an example, the first target material 34 may have first to fourth regions 34a to 34d. The first to fourth regions 34a to 34d may contain first to fourth conductive impurities 36a to 36d, respectively. For example, the first to fourth conductive impurities 36a to 36d may include phosphorus, boron, carbon, and protons, respectively. The laser device 40 may provide the same dose of the laser beam 42 to each of the first to fourth regions 34a to 34d. Alternatively, the laser beam 42 may be provided with different doses to each of the first to fourth regions 34a to 34d.

FIG. 7 shows the emission process of the first to fourth conductive impurities 36a to 36d according to the movement of the laser beam 42 of FIG. 6 .

Referring to FIG. 7 , when a laser beam 42 is sequentially applied to the first to fourth regions 34a to 34d, the first to fourth conductive impurities 36a to 36d may be individually emitted. .

8a to 8d show an example of the substrate doping method of FIGS. 2 to 3 . 9 is a circuit diagram showing a semiconductor device formed by the substrate doping method of FIGS. 8A to 8D.

Referring to FIGS. 8A and 9 , a gate insulating layer 19 may be formed on the substrate 10 . The first mask pattern 22 may be formed on the gate insulating layer 19 . The first mask pattern 22 may partially expose the gate insulating layer 19 . The first conductive impurity 36a may pass through the gate insulating layer 19 and be implanted into the substrate 10 . The first conductive impurities 36a may form first conductive impurity regions 52 in the substrate 10 along the first mask pattern 22 . For example, the first conductive impurity regions 52 may respectively include a source and a drain of the NMOS transistor 62a. After that, the first mask pattern 22 may be removed.

Referring to FIGS. 8B and 9 , the second mask pattern 24 may be formed on the gate insulating layer 19 . The second conductive impurity 36b may be implanted into the substrate 10 . The second conductive impurities 36b may form second conductive impurity regions 54 in the substrate 10 along the second mask pattern 24 . For example, the second conductive impurity regions 54 may respectively include a source and a drain of the PMOS transistor 64a.

Referring to FIG. 8C , the second mask pattern 24 may be removed.

Referring to FIGS. 8D and 9 , an interlayer insulating layer 56 may be formed on the gate insulating layer 19 . The pad electrodes 58 may pass through the interlayer insulating layer 56 and the gate insulating layer 19 and be formed on the first and second conductive impurity regions 52 and 54 . The first gate electrode 62 may be formed in the interlayer insulating layer 56 between the first conductive impurity regions 52 . In addition, the second gate electrode 64 may be formed in the interlayer insulating layer 56 between the second conductive impurity regions 54 . The NMOS transistor 62a may include first conductive impurity regions 52 and a first gate electrode 62 . The PMOS transistor 64a may include second conductive impurity regions 54 and a second gate electrode 64 .

10 shows a substrate doping method according to an example of the present invention. 11 to 13 show an example of the substrate doping method of FIG. 10 .

10 to 12, a substrate 10 is provided (S10). The providing of the substrate 10 ( S10 ) may include applying the conductive impurity solution 70 ( S12 ) and drying the conductive impurity solution 70 ( S14 ).

Referring to FIGS. 10 and 11 , a conductive impurity solution 70 may be provided on the substrate 10 (S12). For example, the conductive impurity solution 70 may be applied on the substrate 10 by a printing method.

Referring to FIGS. 10 and 12 , the conductive impurity solution 70 may be dried (S14). The conductive impurity solution 70 may include a second target material 72 and a solvent 74 . The second target material 72 may be a source of conductive impurities 36 to be implanted into the substrate 10 . The solvent 74 may dissolve the second target material 72 . The solvent 74 may be dried naturally or by heat. For example, solvent 74 may include alcohol, deionized water, or a supercritical material. The second target material 72 may have a solid state.

10 and 13, the laser device 40 provides a laser beam 42 to the second target material 72 (S22). The laser beam 42 may generate electrons (not shown) and conductive impurities 36 from the second target material 72 . Conductive impurities 36 may be implanted into the substrate 10 .

Then, the second target material 72 may be removed.

14 to 16 show an example of the substrate doping method of FIG. 10 .

Referring to FIGS. 10 and 14 , a conductive impurity solution 70 is applied on the substrate 10 within the mask pattern 20 (S12). The mask pattern 20 may define a region where the conductive impurity solution 70 is applied.

Referring to FIGS. 10 and 15 , the conductive impurity solution 70 is dried ( S14 ) to form a second target material 72 in the mask pattern 20 .

Referring to FIGS. 10 and 16 , a laser beam 42 is provided to the second target material 72 in the mask pattern 20 (S22). The second target material 72 may emit conductive impurities 36 into the substrate 10 . The mask pattern 20 may define an implantation region of the conductive impurities 36 .

After that, the mask pattern 20 and the second target material 72 may be removed.

In the above, the embodiments of the present invention have been described with reference to the accompanying drawings, but those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features. You will understand that it can be. Therefore, it should be understood that the above-described embodiments and application examples are illustrative in all respects and not restrictive.

Claims (16)

providing a substrate;
providing a target on the substrate; and
Injecting conductive impurities of the target into the substrate by providing a laser beam to the target separated from the substrate;
The step of providing the laser beam includes accelerating the conductive impurity into the substrate. According to claim 1,
The step of providing the substrate includes forming a mask pattern exposing an implantation region of the substrate. According to claim 2,
The target is spaced apart on the substrate and aligned with the implant region.
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