TWI696207B - Test structure for charged particle beam inspection and method for defect determination using the same - Google Patents

Abstract

A test structure for charged particle beam inspection includes an interconnecting line extending along an X direction and a plurality of first lines and a plurality of second lines extending along a Y direction and alternately arranged along the X direction. Each first line and each second line has a first terminal connected to a same side of the interconnecting line and a second terminal opposite to the first terminal. A first gate structure extends along the X direction and strides across the first terminal of each first line and each second line. A second gate structure extends along the X direction and strides cross the second terminal of each first line and each second line. The electrical coupling between the first lines and the second lines are controlled by the first gate. The electrical coupling of the first lines to a ground pad is controlled by the second gate.

Description

Detection structure used for detection of charged particle beam and detection method using it to detect defects

The invention relates to a semiconductor element detection structure and a defect detection method using the same, in particular to a detection structure for charged particle beam (charged particle beam) detection and a method for detecting electrical defects of a semiconductor element .

Charged particle beam inspection (charged particle beam inspection) is a non-destructive defect detection method, which is mainly used to detect major electrical defects that may lead to scrapping of semiconductor components, such as short circuit defects (short) between circuits and open circuit defects (open ) Or leakage current defect (leakage). Compared to conventional methods, wafer acceptability testing (WAT) must be performed after the subsequent metallization process is completed. Electrical performance and electrical anomalies are measured with fixed probe equipment. Charged particle beam detection can be used in semiconductor devices. After completing part of the process, inline test whether there are electrical defects between the completed structures. It can be detected without making electrode pads by metallization process. It can reflect online process problems more immediately. In terms of industry, it has significant timeliness advantages, making this technology widely used in the manufacture of high-end semiconductor devices.

The charged particle beam detection method usually scans the sample surface with a tiny focused charged particle beam (electron beam or ion beam), so that the electrons (or ions) collide with the sample surface in an inelastic manner, exciting some low-energy secondary electrons , And absorb these with a detector near the sample surface The excited secondary electronic signal is imaged. The surface potential of the sample will affect the yield of secondary electrons. The higher the potential, the smaller the secondary electron yield, the weaker the signal strength measured by the detector, and the darker area will appear after imaging, generally called dark voltage Contrast (dark voltage contrast, DVC). Conversely, the lower the sample surface potential, the higher the secondary electron yield and the stronger the signal intensity measured by the detector, which will show brighter areas after imaging, generally known as bright voltage contrast (BVC). According to the above characteristics, a gray-scale image corresponding to the relative difference in the surface potential of the sample can be obtained, and by analyzing the gray-scale image, it can be determined whether there is an electrical defect in the sample.

The conventional charged particle beam detection method needs to design different detection structures for different types of electrical defects such as short circuit, open circuit, or leakage, such as a comb structure to test short circuit defects, and a continuously curved snake shape (serpentine) structure to test open defects, not only occupy more wafer area, but also increase the detection and analysis time. Therefore, there is still a need in the art for an improved inspection structure and method for inspecting defects to improve the deficiencies of the aforementioned conventional technologies.

An object of the present invention is to provide a detection structure for a charged particle beam detection and a detection method for detecting defects using the same, which includes a gate channel region that can be controlled on/off by scanning with a charged particle beam, so that The detection structure can be applied to detect different types of electrical defects, which improves the deficiencies of the above-mentioned conventional techniques.

One aspect of the present invention provides a detection structure for charged particle beam detection, which includes a substrate, and a circuit pattern is located in the substrate. The line pattern includes a connecting line extending along an X direction; and a plurality of first lines and a plurality of second lines extending along a Y direction and alternating along the X direction Arranged on one side of the connection line. Each of the first line and the second line includes a first end connected to the connection line and a second end opposite to the first end, the X direction and the Y direction are perpendicular to each other. A first gate structure is located on the substrate, extends along the X direction and spans the first ends of each first line and each second line. A second gate structure is located on the substrate, extends along the X direction and spans the second ends of each first line and each second line.

In some embodiments, the first lines, the second lines, and the connecting line are integrally formed. The second end of each first line is electrically connected to a ground, and the second end of each second line is electrically floating.

In some embodiments, the regions covered by the first gate structure of each of the first circuit and the second circuit respectively include a first channel area, and each of the first circuit and each of the second circuit are separated by the second The areas covered by the gate structure respectively include a second channel area.

In some embodiments, when both the first channel regions and the second channel regions are closed, the first lines and the first channels between the first gate structure and the second gate structure Both lines are electrically floating and electrically isolated from each other.

In some embodiments, when the first channel regions are closed and the second channel regions are on, the first lines between the first gate structure and the second gate structure are electrically Grounded, the second lines are electrically floating and electrically isolated from the first lines.

In some embodiments, when the first channel regions and the second channel regions are both on, the first lines and the first channels between the first gate structure and the second gate structure Two-line mutual The phases are electrically connected and electrically grounded.

Another aspect of the present invention provides a charged particle beam detection method, including the following steps. First, a detection structure is provided, including a circuit pattern, a first gate structure, and a second gate structure. The line pattern includes a plurality of first lines and a plurality of second lines, extending along a Y direction and alternately arranged along a X direction and connected to one side of a connecting line. The first gate structure and the second gate structure extend along the X direction and are arranged in parallel along the Y direction, respectively crossing the opposite ends of the first lines and the second lines, the The first gate structure controls the electrical connection between the first lines, the second lines and the connection line, and the second gate structure controls the electrical connection between the first lines and a ground. The detection structure further includes an interlayer dielectric layer covering the circuit pattern, the first gate structure and the second gate structure, wherein an upper surface of the interlayer dielectric layer reveals electrical connections to the first circuits A plurality of first line contact plugs, a plurality of second line contact plugs electrically connected to the second lines, a first gate contact plug electrically connected to the first gate structure, and the second gate The second gate electrode electrically connected to the pole structure contacts the plug. Next, a charged particle beam is used to scan a scanning area of the upper surface of the interlayer dielectric layer to obtain a voltage contrast image of the first line contact plugs and the second line contact plugs. Then, the voltage comparison image is analyzed to determine one of the electrical defects of the detection structure.

In some embodiments, the scanning area includes the first line contact plugs and the second line contact plugs, but does not include the first gate contact plugs and the second gate contact plugs.

In some embodiments, the scanning area includes the first line contact plugs, the second line contact plugs, and the second gate contact plugs, but does not include the first gate contact plugs.

In some embodiments, the scanning area includes the first line contact plugs, the first Two line contact plugs, the second gate contact plug and the second gate contact plug.

One feature of the present invention is to control the on or off of the first channel region by controlling whether the charged particle beam scans to the first gate contact plug, and whether to scan to the second gate contact plug Plug to control the on or off of the second channel area, which can easily switch the electrical connection type of the detection structure during online detection, so that the detection structure can be applied to detect different types of electricity such as short circuit, open circuit or leakage Compared with conventional defects, different detection structures need to be designed for different types of electrical defects, which can save the wafer area occupied by the detection structure and shorten the detection time.

10: Inspection structure

100: base

102: Insulation structure

110: line pattern

112: connection line

116: First line

116a: first end

116b: Second end

118: Second line

118a: first end

118b: second end

119: Doped area

210: Scanning area

220: Scanning area

230: Scanning area

212: Scanning trajectory

312: Detector

314: Secondary electronic signal

316: substrate leakage current

318: Gate leakage current

320: on current

321: On current

322: conduction current

412: Short circuit or leakage defect

122: First gate structure

122a: first passage area

124: Second gate structure

124a: Second passage area

130: Interlayer dielectric layer

131: upper surface

132: First gate contact plug

134: second gate contact plug

136: First line contact plug

138: Second line contact plug

414: Open circuit defect

416: Open circuit defect

X: direction

Y: direction

A-A': Tangent

B-B': Tangent

C-C': Tangent

Figures 1 to 5 are schematic diagrams of a detection structure for charged particle beam detection according to an embodiment of the present invention, wherein: Figures 1 and 2 are top views; and Figure 3 is along A in Figure 2 -A' tangent cross-sectional schematic; Figure 4 is a cross-sectional schematic view along BB' tangent in Figure 2; Figure 5 is a cross-sectional schematic view along BC' tangent in Figure 2;

FIGS. 6 to 10 are charged particle beam defect detection methods according to an embodiment of the present invention, wherein: FIG. 6 is a top view illustrating the scanning range and scanning trajectory of the charged particle beam; FIG. 7 is along the fourth The schematic cross-sectional view of the BB' tangent line shown in the figure; Figure 8 is the cross-sectional schematic view along the CB' tangent line shown in Figure 5; Figure 9 is the cross-sectional BB' tangent line shown in Figure 4 Schematic cross-section of Figure 10; in (a), part (a) illustrates the voltage comparison image when no defect is detected, and (b) part illustrates the detection Contrast image of voltage at defect.

Figures 11 to 14 and 14A are charged particle beam defect detection methods according to another embodiment of the present invention, wherein: Figure 11 is a top view illustrating the scanning range and scanning trajectory of the charged particle beam; Figure 12 is A schematic cross-sectional view along the BB' tangent line shown in Figure 4; Figure 13 is a schematic cross-sectional view along the CB' tangent line shown in Figure 5; in Figure 14, part (a) illustrates unchecked The voltage comparison image when a defect is detected, part (b) illustrates a voltage comparison image when a defect is detected; FIG. 14A illustrates another voltage comparison image when a defect is detected.

Figures 15 to 18 are charged particle beam defect detection methods according to yet another embodiment of the present invention, wherein: Figure 15 is a top view illustrating the scanning range and scanning trajectory of the charged particle beam; Figure 16 is along Fig. 4 is a schematic cross-sectional view of BB' tangent line; Fig. 17 is a cross-sectional schematic view along BC' tangent line shown in Fig. 5; Fig. 18, part (a) illustrates when no defect is detected (B) Illustrates the voltage comparison image when a defect is detected.

In order to enable those of ordinary skill in the art of the present invention to further understand the present invention, the preferred embodiments of the present invention are specifically enumerated below, and in conjunction with the accompanying drawings, the image sensor of the present invention and its manufacturing method are described in detail And the desired effect. For ease of presentation and easy understanding, the drawings are not shown in the actual size or scale of the finished product, so the size or scale of the components in the drawings are only for illustration It is not intended to limit the scope of the invention.

The detection structure provided by the present invention is manufactured in the same process as other semiconductor devices on the substrate, and may be a test key structure fabricated in the scribe line area of the substrate to monitor process variation, evaluate process margins, or detect possible defects in semiconductor devices. The following uses a planar metal-oxide-semiconductor field-effect transistor (MOSFET) process as an example to illustrate the detection structure, it should be understood that other semiconductor processes can also be used to make this Invented detection structure, such as Fin field-effect transistor (FinFET) process.

Figures 1 to 5 are schematic diagrams of a detection structure 10 according to an embodiment of the present invention, wherein Figures 1 and 2 are top views, and Figures 3 to 5 are along A- in Figure 2 A cross-sectional schematic diagram of A'tangent, BB' tangent and CC' tangent.

Please refer to FIG. 1, the detection structure 10 includes a substrate 100, an insulating structure 102 is formed in the substrate 100, and the circuit pattern 110 is defined in the substrate 100. The substrate 100 is, for example, a silicon substrate, a silicon-on-insulator substrate, a group 3-5 semiconductor substrate, etc., but is not limited thereto. The line pattern 110 has a comb-shaped top-view shape, including a connecting line 112 (or called a comb base) extending along the X direction, and a plurality of first lines 116 and a plurality of second lines 118 , Each extending along the Y direction and alternately arranged along the X direction and connected to the same side of the connection line 112, separated from each other by the insulating structure 102. The X and Y directions are perpendicular to each other. Each first line 116 includes a first end 116 a connected to the connection line 112 and a second end 116 b away from the connection line 112 relative to the first end 116 a. Similarly, each second line 118 includes a first end 118a connected to the connection line 112 and a second end 118b remote from the connection line 112 relative to the first end 118a. According to an embodiment of the invention, the length of the second end 116b is longer than the second end 118b for connecting to a ground. The first line 116, the second line 118, and the connection line 112 The insulating structure 102 is defined in the substrate 100, and the three are integrally formed. The conventional shallow trench insulation (STI) structure process may be used to form the insulating structure 102, which will not be repeated here.

The second end 116b of the first line 116 is used to ground the detection structure 10. The grounding mechanism can be achieved by electrically connecting the second end 116b to a ground (GND), or to a potential It is implemented on a semiconductor structure (not shown) or substrate 100 that is not affected by charged particle beam scanning. The semiconductor structure where the potential is not substantially affected by the scanning of the charged particle beam may be a grounding pool defined by the insulating structure 102 in the substrate 100 and integrally formed with the circuit pattern 110, which has a relatively high capacitance In order to withstand the charges generated by the scanning of the charged particle beam, the potential changes in the scanning area are stabilized. It is also possible to obtain a capacitance effect as if it is connected to the collection point by extending the length of the second end 116b to a sufficient length. In contrast, the second end 118b of the second line 118 is electrically floating. In particular, the present invention does not limit the length of the second end 116b of the first line 116 to be greater than the length of the second end 118b of the second line 118, as long as the second end 116b can implement a grounding mechanism . In other embodiments, the second ends 116b and 118b may be flush.

The first line 116 and the second line 118 may have the same line width and be arranged equidistantly along the X direction. The line width and spacing of the first line 116 and the second line 118 can be adjusted according to different detection purposes. For example, when the inspection structure 10 is used as a conventional inspection, the first wiring 116 and the second wiring 118 may have a minimum line width and a minimum spacing, simulating the tightest pattern that other semiconductor elements on the substrate may allow for design. When the inspection structure 10 is used to evaluate the process margin, multiple sets of inspection structures 10 with different line widths and spacing combinations can be made at the same time. By scanning these inspection structures 10 separately, the minimum line width achievable by the process can be evaluated And spacing.

Please continue to refer to Figure 1. The detection structure 10 further includes first gate structures 122 parallel to each other And the second gate structure 124 is disposed on the substrate 100, each extending along the X direction, respectively crossing the first ends 116a, 118a and the second ends of the first lines 116 and the second lines 118 116b, 118b. The area covered by the first gate structure 122 of each first line 116 and each second line 118 is a first channel region 122a (marked in FIGS. 4 and 5). The area covered by the second gate structure 134 of each first line 116 and each second line 118 is a second channel region 124a (marked in FIGS. 4 and 5). One feature of the present invention is that the first gate structure 122 and the second gate 118 are controlled by the first gate structure 122 to control the on or off of the first channel region 122a. The electrical connection (through the connection line 112) or the electrical isolation between the second gate structures 124, and the second gate structure 124 controls the on or off of the second channel region 122a to control the first line 116 Grounding (through the second end 116b) or floating makes the detection structure 10 applicable to detect different types of electrical defects. The first gate structure 122 and the second gate structure 124 may be conventional polysilicon gates or metal gates, and the detailed manufacturing process will not be repeated here.

Please refer to Figure 2 to Figure 5. According to an embodiment of the present invention, the detection structure 10 may further include an interlayer dielectric layer 130 on the substrate 100 and covering the circuit pattern 110, the first gate structure 122 and the second gate structure 124. A plurality of first line contact plugs 136 and a plurality of second line contact plugs 138 are located in the interlayer dielectric layer 130 and are arranged between the first gate structure 122 and the second gate structure 124 along the Y direction, respectively The first circuit 116 and the second circuit 118 are electrically connected to the first circuit 116 and the second circuit 118 respectively, and the top is exposed from the upper surface 131 of the interlayer dielectric layer 130. At least one first gate contact plug 132 is disposed on the first gate structure 122 and electrically connected to the first gate structure 122, and the top portion is exposed from the upper surface 131 of the interlayer dielectric layer 130. At least one second gate contact plug 134 is disposed on the second gate structure 124 and electrically connected to the second gate structure 124, and the top portion is exposed from the upper surface 131 of the interlayer dielectric layer 130. It is worth noting that, as shown in FIG. 2, in the projection along the Y direction, the first gate contact plug 132 and the second gate contact plug 134 are located on the same side outside the line pattern 110, And the first gate contact plug 132 is farther from the circuit pattern 110 than the second gate contact plug 134. It should be noted that Figure 2 and FIG. 6, FIG. 10, FIG. 11, FIG. 14, FIG. 15 and FIG. 18 simultaneously show the line pattern 110, the first gate structure 122, the second gate structure 124, and the first line contact The plug 136, the second line contact plug 138, the first gate contact plug 132, and the second gate contact plug 134 are to facilitate understanding of the configuration and orientation of these elements. During the process of charged particle beam detection, The circuit pattern 110, the first gate structure 122, and the second gate structure 124 are actually covered by the interlayer dielectric layer 130, and are not directly scanned by the charged particle beam.

Please refer to FIGS. 3 to 5. According to an embodiment of the present invention, the surfaces of the first circuit 116, the second circuit 118 and the connection circuit 112 may include a doped region 119. After forming the first gate structure 122 and the second gate structure 124, an ion implantation process may be performed on the substrate 100, such as a source/drain ion implantation process, to implant the conductive doping first The surfaces of the first wiring 116, the second wiring 118 and the connection wiring 112 covered by the gate structure 122 and the second gate structure 124 form a doped region 119. The doped regions 119 on both sides of the first channel region 122a and the second channel region 124a are source/drain regions. In other embodiments employing strained silicon technology, the doped region 119 may be an epitaxial silicon layer formed by epitaxial growth, such as SiP or SiGe. The surface of the doped region 119 may further include a metal silicide layer (not shown) to provide a better contact surface for the first circuit contact plug 136 and the second circuit contact plug 138. In addition, the substrate 100 may include a well region (not shown), surrounding each doped region 119 to provide better insulation between the substrate 100 and the doped region 119.

Another feature of the present invention is that, because the first gate structure 122 and the second gate structure 124 are electrically floating, charged particle beam detection is performed, for example, scanning the first gate contact plug with an electron beam of a predetermined energy When 132 and/or the second gate contacts the plug 134, the surface of the first gate contact plug 132 and/or the second gate contact plug 134 accumulates a positive charge and generates a potential, which is equal to the first gate The gate structure 122 and/or the second gate structure 124 apply a gate voltage with a voltage value sufficient to make the first channel region 122a and/or Or the second channel region 124a is turned on. In this way, whether the first gate contact plug 132 and/or the second gate contact plug 134 are scanned by the electron beam can be conveniently used to control the first gate structure 122 and the second gate structure during online detection The electrical connection between the first line 116 and the second line 118 between 124 and the electrical connection between the first line 116 and the ground. According to an embodiment of the present invention, when the detection structure 10 is used for e-beam detection, the first channel region 122a and the second channel region 124a can preferably pass the first gate structure 122 and the second gate The gate structure 124 is an N-type channel region turned on by applying a positive gate voltage. The doped region 119 is preferably an N+ doped region formed on the P-type substrate 100 (or P-type well region).

Hereinafter, some embodiments of defect detection using the inspection structure 10 will be described. As described above, in the projection along the Y direction, the first gate contact plug 132 and the second gate contact plug 134 are located on the same side outside the line pattern 110, and the first gate contact plug 132 is farther from the circuit pattern 110 than the second gate contact plug 134. With this design, it can be easily adjusted whether the scanning ranges 210, 220 and 230 of the charged particle beam include the first gate contact plug 132 or the second gate contact plug 134 to control the first channel area 122a or the second channel area The off or on of 124a makes the detection structure 10 applicable to the detection of different types of electrical defects.

6 to 10 illustrate a charged particle beam defect detection method according to an embodiment of the present invention, used to detect whether the detection structure 10 has electrical defects such as substrate leakage current or gate leakage current. Figure 6 is a top view, Figures 7 and 9 are schematic cross-sectional views through the first line 116 along the Y direction, Figure 8 is a cross-sectional schematic view through the second lines 118 along the Y direction, Figure 10 Part (a) of Fig. exemplifies the measurement result of the abnormality not detected, and part (b) of Fig. 10 illustrates the measurement result of the abnormality detected.

Please refer to part (a) of Figure 6, Figure 7, Figure 8, and Figure 10. First, provide a test Structure 10, the structure of the detection structure 10 is as shown in Figures 2 to 5 above, and will not be repeated here. Next, scan a scanning area 210 on the surface of the detection structure 10 (ie, the upper surface 131 of the interlayer dielectric layer 130) with a charged particle beam (for example, an electron beam) using the scanning trajectory 212 in the upper left of FIG. 6 to obtain A voltage comparison image of one of the first line contact plug 136 and the second line contact plug 138. The scanning trajectory 212 is back and forth along the Y direction and gradually advances along the X direction, and sequentially scans alternate rows of first line contact plugs 136 and second line contact plugs 138 in sequence. The scanning area 210 includes the first line contact plug 136 and the second line contact plug 138 between the first gate structure 122 and the second gate structure 124, but does not include the first gate contact plug 132 and the second Second gate contact plug 134. In other words, the electron beam does not cause positive charges to accumulate on the surfaces of the first gate contact plug 132 and the second gate contact plug 134, so the first gate structure 122 and the second gate structure 124 are not applied. Any voltage, that is, both the first channel region 122a and the second channel region 124a are off during scanning, so that the first line 116 and the second line 118 are located in the first gate structure 122 and the second gate structure The portions between 124 are each in a floating state. The positive charges generated by the first line contact plug 136 and the second line contact plug 138 after being scanned by the electron beam are accumulated on the surfaces of each first line contact plug 136 and each second line contact plug 138, suppressing secondary electrons Generation, making the detector 312 measure the weak secondary electronic signal 314 (for simplicity, Figures 7 and 8 only show one of the first line contact plug 136 or the second line contact plug 138 A schematic diagram of positive charge accumulation after being scanned by an electron beam). After imaging, as shown in part (a) of FIG. 10, both the first line contact plug 136 and the second line contact plug 138 between the first gate structure 122 and the second gate structure 124 will exhibit dark voltage Contrast (dark voltage contrast, DVC).

Please refer to Figure 9 and Figure 10(b). When an abnormality in the process results in a substrate leakage current 316 or a gate leakage current 318 between the doped region 119 and the substrate 100 (or well region), the first line contact plug 136 and the second line contact plug 138 The positive charge generated by the electron beam scanning will be guided to the substrate 100 or the ground GND through the path of the substrate leakage current 316 or the gate leakage current 318, so it will not Accumulated on the surfaces of the first line contact plug 136 and the second line contact plug 138, the secondary electrons have a higher yield, and the detector 312 can measure the stronger secondary electron signal 314, which is bright Bright voltage contrast (BVC). Since the base leakage current 316 and the gate leakage current 318 are usually systemic defects, when the detection structure 10 is detected to have a defect of the base leakage current 316 or the gate leakage current 318, most areas of the detection structure 10 will generally exist. That is, as shown in part (b) of FIG. 10, the first line contact plug 136 and the second line contact plug 138 between the first gate structure 122 and the second gate structure 124 will each exhibit a bright voltage contrast . It should be noted that when there is a substrate leakage current 316 or a gate leakage current 318 in the detection structure 10, the detection structure 10 cannot detect the first line 116, the second line 118, and the first line contact plug as described below Short circuit, open circuit, or leakage current defect between 136 and the second line contact plug 138. The detection method in FIG. 6 can be used to detect system defects such as substrate leakage current 316 or gate leakage current 318, and can also be used to detect the detection reliability of the detection structure 10 itself.

FIGS. 11 to 14 illustrate a charged particle beam defect detection method according to another embodiment of the present invention, used to detect whether there is a short circuit or leakage current defect between the first line 116 and the second line 118, or to detect the first line 116 Whether there is open circuit defect. FIG. 11 is a top view, FIG. 12 is a schematic cross-sectional view through the first line 116 along the Y direction, FIG. 13 is a cross-sectional schematic view through the second line 118 along the Y direction, and FIG. 14(a) Some examples exemplify measurement results where no abnormality is detected, and parts (b) and 14A of FIG. 14 illustrate measurement results where abnormality is detected. The detection method described in this embodiment is different from the previous embodiments described in FIGS. 6 to 10 in that, as shown in FIG. 11, the scanning area 220 of the electron beam covers the first gate structure 122 and the second gate The first line contact plug 136 and the second line contact plug 138 between the structures 124 also cover the second gate contact plug 134, but not the first gate contact plug 132. During scanning, the scanning trajectory 212 of the electron beam is also moved back and forth along the Y direction and along the X direction, after scanning to the second gate contact plug 134, and then sequentially scanning the alternate rows of first line contact plugs Plug 136 and second line contact plug 138.

Please refer to FIGS. 12 and 14 (a), when the electron beam scans to the second gate contact plug 134, it will cause a positive charge to accumulate on the surface of the second gate contact plug 134 to generate a potential, which is equal to The second gate structure 124 applies a gate voltage with a voltage value sufficient to turn on the second channel region 124a of the first line 116, so that the positive charge caused by the electron beam scanning the first line contact plug 136 can be transferred first The path to the first line 116 is then led to the ground GND through the path of the conducting current 320, and will not accumulate on the surface of the first line contact plug 136, so that the secondary electrons have a higher yield, the detector 312 can measure The stronger secondary electronic signal 314 will show a bright voltage contrast during imaging, as shown in part (a) of Figure 14.

Please refer to the left side of Figure 13 and part (a) of Figure 14. The first gate contact plug 132 is not scanned by the electron beam, and no positive charge is accumulated on its surface, that is, the first gate structure 122 is not applied with the gate voltage, so that the first channel of the second circuit 118 The area 122a is turned off during the scanning process, so that the second line 118 between the first gate structure 122 and the second gate structure 124 is isolated from the connection line 112 and thus electrically isolated from the first line 116. Please refer to the right side of FIG. 13, although the second channel region 124a of the second line 118 is also in the on state (because it is controlled by the second gate structure 124), the second end 118b of the second line 118 is electrically floating Floating, no charge leakage path is provided. Therefore, the positive charge caused by the second line contact plug 138 being scanned by the electron beam will accumulate on the surface, suppressing the yield of secondary electrons, so that the detector 312 can measure the weak secondary electron signal 314 during imaging A dark voltage contrast is presented, as shown in part (a) of FIG. 14, and is alternately arranged with the first line contact plugs 136 exhibiting a bright voltage contrast.

Please refer to FIG. 14 (b), when there is a short circuit or leakage defect 412 between the adjacent first line 116 and the second line 118, for example, due to abnormal patterning process of the substrate 100, poor insulation of the insulating structure 102, and interlayer dielectric The short circuit or leakage defect caused by poor insulation of layer 130 or other factors will cause the positive charge accumulated on the surface of the second line contact plug 138 to flow to the first line through the short circuit or leakage defect 412 116 is further led to the ground terminal GND, causing the second line contact plug 138 which should originally exhibit a dark voltage contrast to exhibit a bright voltage contrast.

Please refer to FIG. 14A, when the first circuit 116 has a disconnection defect 414, for example, a disconnection due to an abnormal patterning process of the substrate 100 or a conduction defect of the first circuit 116 due to contamination particles or other reasons, the fault is located at The positive charge generated by the first line contact plug 136 on the disconnection section after being scanned by the electron beam cannot be directed to the ground terminal GND, so that it exhibits a first line contact different from other normal areas due to the accumulation of positive charge The dark voltage comparison of the plug 136. Since the pattern of the defect area is obviously different from the pattern of other normal areas, the defect can be easily detected. The design layout pattern and imaging pattern can be compared, and the difference in resistance value can be analyzed according to the gray-scale degree of the image, and the possible defect types and abnormal causes can be evaluated.

15 to 18 illustrate a charged particle beam defect detection method according to yet another embodiment of the present invention, which is used to detect whether a second circuit has an open defect. Figure 15 is a top view, Figure 16 is a schematic cross-sectional view through the first line 116 along the Y direction, Figure 17 is a cross-sectional schematic view through the second line 118 along the Y direction, Figure 18(a) Some examples exemplify measurement results where no abnormality is detected, and part (b) of FIG. 18 illustrates example measurement results where abnormality is detected. The detection method described in this embodiment is different from the embodiments described above in FIGS. 6 to 10 in that, as shown in FIG. 15, the scanning area 230 of the electron beam covers the first gate structure 122 and the second gate The first line contact plug 136 and the second line contact plug 138 between the pole structures 124 also cover the second gate contact plug 134 and the first gate contact plug 132. During scanning, the scanning trajectory 212 of the electron beam is also moved back and forth along the Y direction and along the X direction. The first gate contact plug 132 and the second gate contact plug 134 are scanned first, and then sequentially scanned The first line contact plug 136 and the second line contact plug 138 are alternately arranged in each row.

Please refer to the right side of Figure 16 and part (a) of Figure 18. The positive charge accumulation caused by the electron beam scanning to the second gate contact plug 134 is equal to applying a gate voltage to the second gate structure 124, which is sufficient to make the second channel region under the second gate structure 124 124a is turned on, so that the positive charge accumulated on the surface of the first line contact plug 136 during the scan can be led to the ground terminal GND through the conduction current 320 path without accumulating on the surface of the first line contact plug 136, causing secondary electrons With a higher yield, the detector 312 can measure a stronger secondary electronic signal 314, which exhibits a bright voltage contrast during imaging, as shown in Figure 18 (a).

Please refer to Figure 17, left side of Figure 16 and part (a) of Figure 18. In this embodiment, the first gate contact plug 132 is also scanned by the electron beam, generating positive charges accumulated on the surface of the first gate contact plug 132, which is equivalent to applying a gate voltage to the first gate structure 122. The voltage value is sufficient to turn on the first channel region 122a under the first gate structure 122, so that the positive charge accumulated on the surface of the second line contact plug 138 during the scan can sequentially pass through the second line 118, the conduction current 321 path, The first end 118a, the connection line 112, the on-current 322 path, the first line 116, the on-current 320 path are led to the ground GND, and will not accumulate on the surface of the second line contact plug 138, making the second line The contact plug 138 also exhibits a bright voltage contrast, as shown in part (a) of FIG. 18.

Please refer to part (b) of FIG. 18, when the second circuit 118 has a disconnection defect 416, for example, a disconnection due to an abnormal patterning process of the substrate 100 or a conduction path interruption of the second circuit 118 due to contamination particles or other factors Open defect, the positive charge generated by the second line contact plug 138 on the open section after being scanned by the electron beam cannot be guided to the ground GND through the path described in the previous paragraph, making it appear different due to the accumulation of positive charge The dark voltage comparison of the second line contact plug 138 in other normal areas.

It should be particularly noted that the detection structure 10 of the present invention is not limited to e-beam detection, but can also be applied to ion beam (FIB) detection. Due to the different types or energies of charged particle beams, the accumulated charge generated after scanning can be positive or negative. The conductivity type of the first channel region 122a and the second channel region 124a can be designed as an N-type channel region or P as the charge generated after scanning is positive or negative (that is, the generated gate voltage is positive or negative) Type channel area.

In summary, the detection structure 10 for charged particle beam detection provided by the present invention mainly includes a plurality of first lines 116 and a plurality of second lines 118 arranged alternately, and crosses the first lines 116 and the The first gate structure 122 and the second gate structure 124 at both ends of the second line 118 are used to form a first channel area 122a and a second channel area 124a at each end of each first line 116 and each second line 118, respectively. After completing the previous process, after the interlayer dielectric layer 130, the first gate contact plug 132, the second gate contact plug 134, the first line contact plug 136, the second line contact plug 138 (inline) detection step, the first line contact plug 136 and the second line contact plug 138 exposed on the upper surface of the interlayer dielectric layer 130 are scanned with an ion beam (such as an electron beam) to obtain the first line contact plug 136 and one of the voltage comparison images of the second line contact plug 138, and the first channel area is controlled by adjusting whether the scanning range of the charged particle beam includes the first gate contact plug 132 and the second gate contact plug 134 Turning on or off of 122a and the second channel region 124a, thereby controlling the electrical connection between the first line 116 and the ground and the electrical connection between the first line 116 and the second line 118. In short, when the scanning range of the charged particle beam does not include the first gate contact plug 132 and the second gate contact plug 134, the first channel region 122a and the second channel region 124a can be both Closed, so that the detection structure 10 can be used to detect substrate leakage current or gate leakage current and other abnormalities. When the scanning range of the charged particle beam includes the second gate contact plug 134 but not the first gate contact plug 132, the second channel region 124a is electrically connected to the first line 116 during the scanning period to ground , So that the first channel region 122a is closed during the scanning period to electrically isolate the second line 118 from the first line 116, so that the detection structure 10 can be used to detect the first line 116 and the second The short circuit or leakage between the lines 118 is abnormal. When the scanning range of the charged particle beam includes both the first gate contact plug 132 and the second gate contact plug 134, both the first channel region 122a and the second channel region 124a are turned on during scanning, and the first Both the line 116 and the second line 118 are electrically connected to the ground, so that the detection structure 10 can be used to detect whether there is an open circuit abnormality between the first line 116 and the second line. Compared with the prior art, different detection structures need to be designed for different types of electrical defects such as short circuit, open circuit, or leakage. The invention can effectively save the wafer area and detection time occupied by the detection structure.

The above are only the preferred embodiments of the present invention, and all changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope of the present invention.

10: Inspection structure

100: base

102: Insulation structure

110: line pattern

112: connection line

116: First line

116a: first end

116b: Second end

118: Second line

118a: first end

118b: second end

122: First gate structure

124: Second gate structure

X: direction

Y: direction

Claims (19)

A detection structure for charged particle beam detection includes: a substrate, a circuit pattern is located in the substrate, the circuit pattern includes: a connection circuit extending in a first direction; and a plurality of first circuits and a plurality of first The two lines are alternately arranged along the first direction, each of the first line and each of the second lines includes a first end and a second end, the first end is connected to the connection line, and Each first line and each second line respectively extend from the first end along a second direction to the second end, and the second end of each first line is electrically connected to a ground end, The second end of each second line is electrically floating, wherein the first direction and the second direction are perpendicular to each other; a first gate structure is located on the substrate and extends along the first direction and Across the first end of each of the first line and each of the second line; and a second gate structure, located on the substrate, extending along the first direction and across each of the first line And the second end of each second line. The detection structure for charged particle beam detection as described in claim 1, wherein the first circuits, the second circuits and the connection circuit are integrally formed. The detection structure for charged particle beam detection as described in claim 1, wherein the areas covered by the first gate structure of each of the first line and each of the second lines respectively include a first channel area, and each of the first A line and each area covered by the second gate structure of the second line respectively include a second channel area. The detection structure for charged particle beam detection as described in claim 3, when both the first channel area and the second channel areas are closed, the first gate structure and the second gate structure The first lines and the second lines are electrically floating and electrically isolated from each other. The detection structure for charged particle beam detection as described in claim 3, when the first channel regions are closed and the second channel regions are on, the first gate structure and the second gate structure The first lines in between are electrically grounded, and the second lines are electrically floating and electrically isolated from the first lines. The detection structure for charged particle beam detection as described in claim 3, when both the first channel region and the second channel regions are on, the first gate structure and the second gate structure The first lines and the second lines in between are electrically connected to each other and electrically grounded. The detection structure for charged particle beam detection as described in claim 1, further comprising: an interlayer dielectric layer on the substrate and covering the circuit pattern, the first gate structure and the second gate structure; A plurality of first line contact plugs are provided on each first line and are electrically connected to each first line; a plurality of second line contact plugs are provided on each second line and are connected to each second Line electrical connection; a first gate contact plug provided on the first gate structure and electrically connected to the first gate structure; and a second gate contact plug provided on the second gate Structurally and electrically connected to the second gate structure The top surface of each of the first line contact plug, the second line contact plug, the first gate contact plug and the second gate contact plug is separately from the interlayer dielectric layer One of the upper surface is exposed. The detection structure for charged particle beam detection as described in claim 7, wherein the first gate contact plug and the second gate contact plug are both located at the projection along the second direction The same side except the circuit pattern, and the first gate contact plug is farther from the circuit pattern than the second gate contact plug. The detection structure for charged particle beam detection as described in claim 1 further includes an insulating structure located in the substrate and isolating the first lines and the second lines. A charged particle beam detection method, comprising: providing a detection structure, including: a line pattern, including a plurality of first lines and a plurality of second lines, alternately arranged along a first direction, each of the first lines and each of the lines The second line includes a first end and a second end, the first end is connected to a connection line, and each of the first line and each of the second lines are respectively along the first end A second direction extends to the second end, wherein the second end of each first line is electrically connected to a ground, and the second end of each second line is electrically floating; a first A gate structure and a second gate structure extend along the first direction, respectively across the opposite ends of the first lines and the second lines, and the first gate structure controls the An electrical connection between the first line, the second lines and the connecting line, the second gate structure controls the electrical connection between the first lines and a ground An interlayer dielectric layer covering the circuit pattern, the first gate structure and the second gate structure, wherein an upper surface of the interlayer dielectric layer reveals a plurality of first electrical connections to the first circuits A line contact plug, a plurality of second line contact plugs electrically connected to the second lines, a first gate contact plug electrically connected to the first gate structure, and a second gate structure Electrically connected second gate contact plug; scanning a scanning area of the upper surface of the interlayer dielectric layer with a charged particle beam to obtain the first line contact plug and the second line contact plug A voltage comparison image; and analyzing the voltage comparison image to determine an electrical defect in the detection structure. The charged particle beam detection method according to claim 10, wherein the charged particle beam is moved back and forth along the second direction and propelled along the first direction to scan the scanning area. The charged particle beam detection method according to claim 10, wherein the charged particle beam is an electron beam. The charged particle beam detection method according to claim 12, wherein the scanning area includes the first line contact plugs and the second line contact plugs, but does not include the first gate contact plugs and the first The second gate contacts the plug. The charged particle beam detection method according to claim 13, wherein when the detection structure has a substrate leakage current defect or a gate leakage current defect, the first line contact plugs and the second line contact plugs are both present Bright voltage comparison. The charged particle beam detection method according to claim 12, wherein the scanning area includes the first line contact plugs, the second line contact plugs, and the second gate contact plugs, but does not include the first A gate contact plug, and the charged particle beam scans the second gate contact plug first, and then scans the first line contact plugs and the second line contact plugs. The charged particle beam detection method according to claim 15, wherein: when there is no short-circuit defect between the first lines and the second lines, the contact plugs of the first lines all exhibit a bright voltage contrast, and The second line contact plugs all exhibit a dark voltage contrast; and when there is a short-circuit defect between the first lines and the second lines, some of the second line contact plugs exhibit a bright voltage contrast. According to the charged particle beam detection method described in claim 15, when these first lines have a disconnection defect, part of the first line contact plugs will exhibit a dark voltage contrast. The charged particle beam detection method according to claim 12, wherein the scanning area includes the first line contact plugs, the second line contact plugs, the second gate contact plugs, and the second gate A contact plug, and the charged particle beam scans the first gate contact plug and the second gate contact plug first, and then scans the first line contact plugs and the second line contact plugs. The charged particle beam detection method according to claim 18, wherein when the first lines and the second lines do not have a disconnection defect, the first line contact plugs and the second line contact plugs are both A bright voltage contrast is presented. When the first lines or the second lines have open defects, some of the first line contact plugs or the second line contact plugs will exhibit dark voltage pairs ratio.

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