阅读说明：本技术 半导体晶片的检测方法 (Method for inspecting semiconductor wafer ) 是由 王龙 于 2021-01-26 设计创作，主要内容包括：本发明公开一种半导体晶片的检测方法,包含提供一晶片,该晶片上定义有多个区域,该多个区域中至少包含有一第一区域以及一第二区域,进行一第一次光刻步骤,以曝露该多个区域中的该第一区域,进行一第一次离子注入步骤,在该第一区域内掺杂离子,其中该第一区域内具有一第一离子注入浓度,进行一第二次光刻步骤,以曝露该多个区域中的该第二区域,进行一第二次离子注入步骤,在该第二区域内掺杂离子,其中该第二区域内具有一第二离子注入浓度,然后分别检测该第一区域与该第二区域的电性特征。(The invention discloses a method for detecting a semiconductor wafer, which comprises the steps of providing a wafer, defining a plurality of regions on the wafer, wherein the plurality of regions at least comprise a first region and a second region, carrying out a first photoetching step to expose the first region of the plurality of regions, carrying out a first ion implantation step to dope ions in the first region, wherein the first region has a first ion implantation concentration, carrying out a second photoetching step to expose the second region of the plurality of regions, carrying out a second ion implantation step to dope ions in the second region, wherein the second region has a second ion implantation concentration, and then respectively detecting the electrical characteristics of the first region and the second region.)

1. A method for inspecting a semiconductor wafer, comprising:

providing a wafer, wherein a plurality of areas are defined on the wafer, and the plurality of areas at least comprise a first area and a second area;

performing a first photolithography step to expose the first region of the plurality of regions;

carrying out a first ion implantation step to dope ions in the first region, wherein the first region has a first ion implantation concentration;

performing a second photolithography step to expose the second region of the plurality of regions;

performing a second ion implantation step to dope ions in the second region, wherein the second region has a second ion implantation concentration; and

the electrical characteristics of the first region and the second region are respectively detected.

2. The detecting method of claim 1, wherein the plurality of regions further includes a third region and a fourth region, and the detecting method further comprises:

performing a third photolithography step to expose the third region of the plurality of regions;

performing a third ion implantation step to dope ions in the third region, wherein the first region has a third ion implantation concentration;

performing a fourth photolithography step to expose the fourth region of the plurality of regions;

performing a fourth ion implantation step to dope ions in the fourth region, wherein the fourth region has a fourth ion implantation concentration;

and respectively detecting the electrical characteristics of the first area, the second area, the third area and the fourth area.

3. The detecting method of claim 2, wherein the first ion implantation concentration, the second ion implantation concentration, the third ion implantation concentration and the fourth ion implantation concentration are different from each other.

4. The method of claim 1, wherein exposing the first region and the second region comprises:

globally forming a first photoresist layer on the wafer;

removing a portion of the first photoresist layer by the first photolithography step using a first photomask, and exposing the first region;

globally removing the first photoresist layer and re-forming a second photoresist layer on the wafer;

using the first photomask, removing part of the second photoresist layer by the second photolithography step, and exposing the second region.

5. The detecting method of claim 4, wherein the first region is covered by the second photoresist layer when the second region is exposed.

6. The method of claim 1, wherein exposing the first region and the second region comprises:

globally forming a first photoresist layer on the wafer;

performing the first photolithography step, focusing an exposure light in the first region, and removing the first photoresist layer in the first region;

removing the first photoresist layer and forming a second photoresist layer on the wafer;

the second photolithography step is performed to focus another exposure light in the second region and remove the second photoresist layer in the second region.

7. The method of claim 1, wherein the step of separately detecting the electrical characteristics of the first region and the second region comprises:

forming at least one electronic element in the first region and the second region respectively; and

wafer Acceptance Test (WAT) is performed on the electronic components in the first area and the second area, respectively.

8. A method for inspecting a semiconductor wafer, comprising:

providing a wafer, wherein a plurality of areas are defined on the wafer, and the plurality of areas at least comprise a first area and a second area;

performing a first photolithography step to expose the first region of the plurality of regions with a first exposure energy and form a first pattern in the first region, wherein the first pattern has a first exposure extremum;

performing a second photolithography step to expose the second region of the plurality of regions with a second exposure energy and form a second pattern in the second region, wherein the second pattern has a second exposure extremum; and

the electrical characteristics of the first region and the second region are respectively detected.

9. The inspection method of claim 8, wherein the first photolithography step and the second photolithography step are performed using the same photomask.

10. The method of claim 8, wherein the step of separately detecting the electrical characteristics of the first region and the second region comprises:

forming at least one electronic element in the first region and the second region respectively; and

wafer Acceptance Test (WAT) is performed on the electronic components in the first area and the second area, respectively.

Technical Field

The present invention relates to the field of semiconductors, and more particularly, to a wafer testing process that reduces wafer loss during Wafer Acceptance Testing (WAT).

Background

In a semiconductor fabrication process, multiple steps are performed on a wafer (wafer) to form a variety of different electronic components on the wafer. In order to ensure the quality of the electronic components, test keys (testkeys) are often formed on scribe lines (scribes) on the wafer, and then Wafer Acceptance Tests (WATs) are performed on the electronic components on the wafer.

Wafer acceptance testing is aimed at making preliminary electrical measurements of the wafer as a basis for wafer quality assurance. The tested electrical parameters, such as capacitance, voltage, resistance …, etc., can ensure the normal operation of the electronic device. Therefore, the electrical parameters of the wafer are tested to reflect whether the wafer has abnormal phenomena during production, and the quality of the device is prevented from being reduced.

Disclosure of Invention

The invention relates to a method for detecting a semiconductor wafer, which comprises the steps of providing a wafer, defining a plurality of regions on the wafer, wherein the plurality of regions at least comprise a first region and a second region, carrying out a first photoetching step to expose the first region of the plurality of regions, carrying out a first ion implantation step to dope ions in the first region, wherein the first region has a first ion implantation concentration, carrying out a second photoetching step to expose the second region of the plurality of regions, carrying out a second ion implantation step to dope ions in the second region, wherein the second region has a second ion implantation concentration, and then respectively detecting the electrical characteristics of the first region and the second region.

The invention relates to a method for detecting a semiconductor wafer, which comprises the steps of providing a wafer, defining a plurality of areas on the wafer, wherein the plurality of areas at least comprise a first area and a second area, carrying out a first photoetching step, exposing the first area in the plurality of areas by first exposure energy, forming a first pattern in the first area, wherein the first pattern has a first exposure extreme value, carrying out a second photoetching step, exposing the second area in the plurality of areas by second exposure energy, and forming a second pattern in the second area, wherein the second pattern has a second exposure extreme value, and respectively detecting the electrical characteristics of the first area and the second area.

The present invention is characterized in that the wafer can be divided into different areas during the wafer testing stage, and the respective manufacturing process and electrical test can be performed in the different areas. Thus, different regions may provide different test parameters and measurements. Therefore, a plurality of sets of experimental results can be measured on the same wafer, thereby reducing the consumption of the wafer and reducing the cost.

Drawings

FIG. 1 is a schematic top view of a semiconductor wafer during inspection thereof according to the present invention;

FIG. 2A, FIG. 2B, FIG. 2C and FIG. 2D are schematic top views of a semiconductor wafer during a photolithography step and an ion implantation step cycle during inspection of the semiconductor wafer according to an embodiment of the present invention;

FIGS. 3A and 3B are top views of a semiconductor wafer illustrating the effect of different exposure energies on exposure extremes of different regions according to another embodiment of the present invention.

Description of the main elements

10: semiconductor wafer

10A first region

10B second region

10C third region

10D fourth region

20A mask layer

20B mask layer

20C mask layer

20D mask layer

40 pattern

Pattern 40

CD1 extreme Exposure

CD2 extreme Exposure

W is doping concentration

X is doping concentration

Y doping concentration

Z is doping concentration

Detailed Description

In order to make the present invention more comprehensible to those skilled in the art, preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

For convenience of explanation, the drawings are only schematic to facilitate understanding of the present invention, and the detailed proportions thereof may be adjusted according to design requirements. The relative positions of elements in the figures described herein are understood by those skilled in the art to refer to relative positions of objects and thus all parts may be turned over to present the same elements, all falling within the scope of the present disclosure and all described herein.

In some embodiments, semiconductor wafer testing is performed by generally assigning a particular experimental parameter to an entire wafer and then performing WAT testing on the semiconductor wafer. For example, taking the effect of the ion implantation concentration in the semiconductor wafer to be tested on the subsequently formed semiconductor device as an example for illustration, a plurality of semiconductor wafers may be provided, one of the semiconductor wafers may be doped with ions of a specific concentration (for example, the ion implantation concentration is N), and then the WAT test may be performed after the electronic device is subsequently formed. Then, ions with different ion concentrations (for example, ion implantation concentrations on the other 3 semiconductor wafers are N +1, N +2, and N +3, respectively) are doped on the other several semiconductor wafers, and then the WAT test is performed after electronic devices are formed. In the above embodiment, a plurality of semiconductor wafers (e.g., 4 wafers) need to be worn to obtain a plurality of experimental test results. Therefore, cost saving is not facilitated.

FIG. 1 is a schematic top view of a semiconductor wafer during inspection of the semiconductor wafer according to the present invention. As shown in fig. 1, a semiconductor wafer 10 is divided into a plurality of regions, for example, a first region 10A, a second region 10B, a third region 10C, and a fourth region 10D. It should be noted that the division of the semiconductor wafer 10 into four regions is merely an exemplary illustration, and the invention is not limited thereto. In other words, the present invention may divide the semiconductor wafer 10 into more or less regions, and also fall within the scope of the present invention.

Fig. 2A, 2B, 2C and 2D are schematic top views of a semiconductor wafer during a photolithography step and an ion implantation step in a process of inspecting the semiconductor wafer according to an embodiment of the invention. First, in fig. 2A, a first photolithography step may be performed with a photomask to form a mask layer 20A (e.g., a photoresist layer) on the semiconductor wafer 10, the mask layer 20A covering other regions except the first region 10A to expose the first region 10A, and then a first ion implantation step is performed on the semiconductor wafer 10 to dope ions with a concentration W in the first region 10A.

Next, as shown in fig. 2B, after removing the mask layer 20A, a photoresist layer (not shown) is formed on the semiconductor wafer 10 again, a second photolithography step is performed with the same photomask used in the step of fig. 2A, a mask layer 20B (e.g., a photoresist layer) is formed on the semiconductor wafer 10, the mask layer 20B covers the other regions except the second region 10B to expose the second region 10B, and then a second ion implantation step is performed on the semiconductor wafer 10 to dope ions with the concentration of X in the second region 10B.

Next, as shown in fig. 2C, after removing the mask layer 20B, a photoresist layer (not shown) is formed on the semiconductor wafer 10 again, a third photolithography step is performed with the same photomask used in the step of fig. 2A, a mask layer 20C (e.g., a photoresist layer) is formed on the semiconductor wafer 10, the mask layer 20C covers the other regions except the third region 10C to expose the third region 10C, and then a third ion implantation step is performed on the semiconductor wafer 10 to dope ions with the concentration Y in the third region 10C.

Next, as shown in fig. 2D, after removing the mask layer 20C, a photoresist layer (not shown) is formed on the semiconductor wafer 10 again, a fourth photolithography step is performed with the same photomask used in the step of fig. 2A, a mask layer 20D (e.g., a photoresist layer) is formed on the semiconductor wafer 10, the mask layer 20D covers the regions except the fourth region 10D to expose the fourth region 10D, and then a fourth ion implantation step is performed on the semiconductor wafer 10 to dope ions with the concentration Z in the fourth region 10D.

It is noted that, when performing the photolithography step (as in the above steps of fig. 2A to 2D), the same photomask is used and the focal length of the exposure light is adjusted to control the exposure area, for example, the exposure light is focused on a specific area, so that only the area can be successfully exposed, and the other areas cannot be successfully exposed. In other words, only one photomask is needed to sequentially expose different regions. For example, in the step of fig. 2A, the exposure light is focused on the upper left half of the semiconductor wafer 10, so that the exposure light is located in the upper left half (the first region 10A is exposed), and the other regions are not exposed. After another photoresist layer is formed again in fig. 2B, the exposure light can be focused on the upper right half of the semiconductor wafer 10, so that the other areas are not exposed in the upper right half (the second area 10B is exposed). Other regions may be analogized. Therefore, the effects of saving the photomask and reducing the cost can be achieved.

Preferably, the ion implantation concentrations W, X, Y, Z are different. And preferably have a certain proportional relationship (e.g., linear relationship) with each other, so that the electrical influence caused by the variation of the ion implantation concentration can be easily calculated by the detector in the subsequent steps.

In the above steps, a cycle of the photolithography step and the ion implantation step is performed. The number of cycles of the photolithography step and the ion implantation step can also be adjusted if the semiconductor wafer 10 is divided into more or less regions. In addition, in the present embodiment, since the first to fourth ion implantation steps are performed on the first to fourth regions 10A to 10D, respectively, the ion implantation concentrations of the first, second, third and fourth regions 10A, 10B, 10C and 10D are independent of each other and are not affected by each other.

Subsequently, electronic components (e.g., transistors, capacitors) may be formed in the respective regions of the semiconductor wafer 10 at the same time, and then WAT testing of the electronic components may be performed to obtain experimental results of the effects of different manufacturing process parameters on the electronic components. For example, different ion implantation concentrations affect the performance of the transistor.

By the above method, ion implantation can be performed on different regions of the same semiconductor wafer 10, and then the electrical characteristics of the electronic devices in each region can be measured. Therefore, multiple sets of experimental data (e.g., data of electrical effects of ion implantation concentration on electronic components) can be measured without using multiple semiconductor wafers. The purpose of saving semiconductor chips and thus saving cost can be achieved.

It is noted that in the steps of the present invention, the photolithography step and the ion implantation step are sequentially performed in each of the different regions, and after the ion implantation step is completed in each region, the electronic devices in each region are formed, and the electrical characteristics of each electronic device are sequentially measured. Therefore, it is preferable that the photolithography step and the ion implantation step are continuously performed between different regions in the steps of the present invention, in other words, other steps are not performed during the cycle of the photolithography step and the ion implantation step, and the subsequent other steps are not performed until all the regions are completely implanted. Therefore, since each ion implantation is performed in a similar environment, the accuracy of the experimental result can be improved.

In the above embodiments, the ion implantation with different concentrations is performed in different regions of the same wafer, that is, the influence of the ion implantation with different concentrations on the experimental results can be obtained through testing. In other embodiments of the present invention, different parameter tests may be performed on different regions of the same wafer, for example, different exposure energies may be used to expose the same pattern on different regions of the same wafer, so that the most suitable exposure threshold (CD) can be tested to improve the efficiency of the subsequent manufacturing process.

For example, fig. 3A and 3B illustrate top views of a semiconductor wafer for detecting the effect of different exposure energies on exposure extremes of different regions according to another embodiment of the present invention. First, as shown in fig. 3A, a photoresist layer (not shown) is formed, and then a first photolithography step (including exposure and development steps) is performed to remove a portion of the photoresist layer, thereby forming a mask layer 20A on the semiconductor wafer 10, wherein the mask layer 20A exposes the first region 10A and covers the other regions, and a pattern 40 is formed in the first region 10A. Wherein the exposure energy of the first lithography step is adjusted (e.g. the exposure energy is E1) and after pattern formation the exposure extremum of the pattern is recorded (e.g. as exposure extremum CD 1).

Next, as shown in fig. 3B, after removing the mask layer 20A in the second region 10B, a photoresist layer (not shown) is formed again, and a second photolithography step (exposure and development step) is performed to remove a portion of the photoresist layer, thereby forming a mask layer 20B on the semiconductor wafer 10, wherein the mask layer 20B exposes the second region 10B and covers the other regions, and a pattern 40' is formed in the second region 10B. Wherein the exposure energy of the second lithography step is adjusted (e.g., exposure energy is E2) and after the pattern 40' is formed, the exposure extremum of the pattern is recorded (e.g., as exposure extremum CD 2).

Subsequently, it is also possible to continue to form patterns in the third region 10C and the fourth region 10D, respectively, and adjust the exposure energy of the lithography step and record the exposure extremum of the pattern. Since the steps are similar to those described above, detailed description is not repeated here.

Similarly, electronic components (e.g., transistors, capacitors) may be formed in various regions of the semiconductor wafer 10 at the same time, and then subjected to WAT testing to obtain experimental results of the effects of different manufacturing process parameters on the electronic components. For example, different exposure energies affect the performance of the transistor. By the method, the influence of different exposure energies on the exposure extreme value of the pattern can be measured on the same wafer, and better exposure energy can be further found out so as to improve the yield of the subsequent semiconductor manufacturing process.

Similarly, in the present embodiment, for example, in the steps of fig. 3A and fig. 3B, the same photo mask may be used to perform the photolithography step respectively, so as to achieve the effect of saving the photo mask.

The present invention is characterized in that the wafer can be divided into different areas during the wafer testing stage, and the respective manufacturing process and electrical test can be performed in the different areas. Thus, different regions may provide different test parameters and measurements. Therefore, a plurality of sets of experimental results can be measured on the same wafer, thereby reducing the consumption of the wafer and reducing the cost.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in the claims of the present invention should be covered by the present invention.