TWI220285B - Semiconductor test structure for clarifying the cause of leakage current - Google Patents

Abstract

The present invention provides a kind of semiconductor test structure for clarifying generation cause of leakage current. The invention contains a well having the first conduction characteristic; and the first isolation device is located in the well. At least the first doped region is located at one side of the first isolation device, and the first doped region has the second conduction characteristic. The second doped region is located in the well that is located at the other side opposite to that of the first isolation region. The second doped region has the first conduction characteristic with its doping concentration larger than that of the well, and is connected externally to a grounding electric-potential. The structure can be used to clarify each kind of leakage current types, for example surface type, field edge type, polysilicon edge type, or gate edge type, caused by junction or oxide layer.

Description

1220285 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a test structure used to clarify the cause of component problems, and particularly to a semiconductor test structure used to clarify the bonding and oxidation of components The cause of the layer leakage problem. [Previous Technology] A semiconductor device is usually composed of several layers of materials with different electrical properties. When these materials come into contact with each other, some phenomena derived from the difference in electrical properties also occur. The results of these contacts will affect the performance of the entire semiconductor device. Conventionally, j unc t i on is used to describe various contacts between semiconductor device materials. The use of junctions between semiconductors and external applied voltage methods, such as forward bias or reverse bias, enables semiconductors to be used as switches, current rectifiers, or amplifiers ), And even integrate these into a semiconductor element. However, due to the thermal motion of the electrons, the internal or external electric field, and the applied voltage, the leakage current (1 ^^ "current) phenomenon caused by the junction is caused. However, the leakage current is known in the small integrated accumulation degree ( The design of integration) can be ignored. However, when the size of semiconductor elements is rapidly reduced and the degree of integration accumulation is rapidly increased, the existence and occurrence of leakage current cannot be ignored. In addition, the bonding between different semiconductor structures It has also become one of the keys to the good performance of the device. However, there are many joint surfaces and leakage currents existing in the semiconductor device =, when the performance or properties of the semiconductor device have problems, it will be difficult to clarify ^

Jade and Invention Explanation (2) The reason for the problem. Especially when there is commonality or similarity between the causes of a problem, it becomes more difficult to find the cause. Therefore, the industry usually designs some test structures to simulate the interim semiconductor device 5 where the problem occurs and find out the cause of the problem. However, improper structural design can not only help to find out the cause of the problem, but also mislead the judgment and increase the design and manufacturing cost of semiconductor components. Therefore, only the correct test structure design can do more with less and quickly and correctly infer the cause of the problem. [Summary of the Invention] In view of the above, one of the objectives of the present invention is to provide a structural design 'to clarify the cause of the leakage current of the junction and the oxide layer, and to correctly reflect the main cause of the problem through the design of three states . Another object of the present invention is to provide a semiconductor structure design for clearing the cause of the leakage current of the junction and the oxide layer, and by amplifying the contribution of the specific cause to find out the main cause of the problem. In order to achieve the above-mentioned object, the present invention provides a semiconductor test structure for clarifying the cause of leakage current, which includes a well having a first electrical isolation element located in the well, and at least one first replacement Location

On one side of the first isolation element, the first doped region has a second conductivity = j τ 2. A well located on the opposite side of the first isolation element: the region has a first conductivity and is doped. The concentration is greater than the well and is externally connected to a ground voltage. -The embodiment will be explained in detail with the accompanying drawings. When Gu Yi understands the purpose, the technical characteristics, the features and the accomplishments of this technology,

1220285 V. Description of the invention (3) Effect 0 Description of drawing number: 10 well 12 First doped region 14 Isolation element 16 Second doped region 18 Polycrystalline silicon structure 2 0 Oxide layer 2 2 First doped gate [Embodiment] The semiconductor design of the present invention can be widely applied to many semiconductor devices: 乂 一 卜 f ΐ can be made using many different semiconductor materials. When two examples of the present invention are used to illustrate the method of the present invention, the steps of those skilled in the art can Modifications of materials and impurities can also be replaced without doubt, without departing from the spirit and spirit of the present invention. ~ ,,, t 't is described in detail with a schematic diagram as follows. In detailing this broad example, the cross-sectional view of a semiconductor structure is semi-conducting. Material, in actual, as a limited three-dimensional space size. The length, width, and depth of the middle shovel are shown in Figure 1. This is one of the inventions; Well 10 'is done, for example, by replacing the P-type ions in a p-bonded test structure. Isolation is used; the semiconductor bottom structure (Shal low Trench τ, such as shallow trench isolation ch Isolation, Yang), is located in the well 10. 1220285 V. Description of the invention (4) The isolation element 14 can be formed by a conventional method. The doped region 12, for example, a heavily doped region, will not be described in detail. Number-of-side of well 1. And can be connected to — 外 _, t Lifan 14 =. In addition, the second doped region 16, such as a region, is formed in the well 10 on the other side of the isolation element 14 at an external ground voltage. In this embodiment, ^ μ ^ A & x 1 j Y, the second doped region 16 separated by t ′ is formed only with the well 10-junction. The size of the test structure is 50um * 500um, but it is not limited to this size). Generally, when calculating the total joint leakage current, the joint area, joint long-term yield, and the product of the edge length and the number of contacts and their respective leakage currents are added to ^. Therefore, the 'Structure Design of Figure 1' enlarges the joint area effect. The leakage current caused by δ area is the main cause of leakage current.

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Figure 2 is a schematic cross-sectional view of a field edge type junction test structure according to the present invention. With Cap! The figure is similar, and several isolation elements are located in the well 10: several first doped regions 12, such as an N-type heavily doped region, are formed in the well 10 that isolates one side of the 7G part 14 and any two The first doped regions 12 are separated by an isolation element 14, and each of the first doped regions 12 can be connected to an external positive volt, for example, a voltage of + 3.6V. In addition, the second doped region 16 is formed in the well 10 on the opposite side of the isolation element η and can be connected to an external ground voltage. In this embodiment, the second doped region 16 is adjacent to the isolation element 14 and forms a joint with both the isolation element 14 and the well. The size of the test structure is 5um * 500U [n, the number is 500 bars', but it is not limited to this size and number. Such a structural design, enlarged connection

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Joint edge effect: The leakage current caused by the joint edge is the main cause for testing. Referring to FIG. 3 is a schematic cross-sectional view of a poly edge (M) junction test structure of the present invention. Similar to FIG. 丨, the second doped region 16 and the isolation element 14 are separated. Similar to FIG. 2, it contains several first doped regions 12, but any two first-doped regions 12 are spaced apart / spaced by several polycrystalline silicon structures located on the well 10 and each The first doped region 12 may be connected to an external positive volt, for example, a voltage of +3.6 volts. This structure design amplifies the polysilicon edge effect, and the leakage current caused by the polysilicon edge during polysilicon etching is the main leakage current. The reason is to perform the test. Next, FIG. 4 is a schematic cross-sectional view of a planar oxide test structure according to the present invention. Similar to FIG. 1, the first doped gate electrode 22, such as an N-type heavily doped gate The electrode is formed on the well 10 on one side of the isolation element 14 and can be connected to an external negative volt, for example, a voltage of -3.6 volts. The second doped region 16, such as a p-type heavily doped region ' The well 1 formed on the opposite side of the isolation element 14 And can be connected to an external ground voltage. In addition, an oxide layer 20 is between the first doped gate electrode 22 and the well 10. In general, when calculating the total oxide layer leakage current, the oxide layer area and oxidation The layer length f, the oxide edge length, the number of contacts, and the product of the respective leakage currents add up to two. Therefore, the structure design in Figure 4 enlarges the oxide area effect. The leakage current caused by the oxide area is the main leakage current. Cause 'to test. Refer to Figure 5 for a cross-section of a field-edge oxide test structure of the present invention.

122〇285 V. Description of the invention A plurality of isolation elements 14 are located in the well 10, and are covered with a layer of oxygen 20 and a first doped gate 22, and the first doped gate 22 may be connected to a negative voltage, such as a voltage of -3.6 volts. The second doped region] 6 is shaped in a well i0 on the opposite side of the isolation element 14 and can be connected to an external ground voltage. In this embodiment, the second doped region 6 is adjacent to the isolation element =, and at the same time forms a joint with the isolation element i4 and the well i0. In this way, the H-large oxide layer edge effect is constructed to test the leakage current induced by the edge of the oxide layer as the main cause of the leakage current. ^ Refer to FIG. 6, which is a schematic cross-sectional view of a gate edge type 2 layer test structure according to the present invention. Similar to FIG. 3, the second doped domain 16 is separated from the isolation element 14. Contains several first doped regions or 12, but between any two first doped regions 12, with several polycrystalline broken structures 18 disks located on the well 10 gasified?? Η phase glare w > / The emulsified layers are spaced apart, and each polycrystalline silicon is connected to an external negative volt, such as a voltage of 3.6 volts. The leakage caused by this box is the main reason for the leakage current of the electric muscle Feng to measure the salt. Capital = The leakage current with K is also related to the number of contacts, so this month using the above test structure t to clear the junction or oxide layer leakage current due to the day, you can also design test structures with different numbers of contacts, such as: Have a smaller number of contacts 'and the other has more & purposes:' This is to clarify the effect of leakage current caused by the number of contacts. Therefore, the present invention provides the cause of the _ _ + current, which includes _P, and is used to make the von 3 P-type well. The first-isolation element is located in the P-type.

Page 10 V. Description of the invention (γ) In the well, at least one

The re-doped region is located on one side of the first isolation element 'and a p-type well on the opposite side of the P-type re-isolated element, with p ground voltage. ^ The degree of miscellaneous spread is greater than that of the P-type well ', and the external connection to a connection r, i is only for explaining the technical ideas and features of the present invention. The purpose is to enable those skilled in the art to understand this technology. The inner valley of the invention is implemented accordingly. When the scope of the patent of the present invention cannot be limited by it, that is, equivalent changes or modifications made in accordance with the spirit disclosed by the present invention should still be covered by the scope of the patent of the present invention.

Page 11 1220285 Brief description of the drawings —_ Figure 1 is a schematic cross-sectional view of one of the present inventions. Area type joint test structure Figure 2 is a schematic cross-sectional view of the test structure ^^ _ Field edge type joint test chart 3 is an evening view of the invention Poiy edge type joint Fig. 4 is a diagram of the present invention. The cross-section of a beta-type oxide test structure is shown in Figure 5. A cross-sectional view of a field-edge oxide layer test structure. Figure 6 is a schematic cross-sectional view of a gate edge type oxide j ° structure of the present invention.

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Claims (1)

A ^ U285 6. Application Patent Scope 1. A semiconductor test junction semiconductor test structure package with a well with a first conduction and a first isolation element at least one first doped region and one doped region with _ one second doped region Located in the well, the second doping concentration is greater than that of the well in the first doped region of the patent application, the range is located in the 'available structure' to clarify the cause of the leakage current, # contains: ^ electrical; in the well; A second conductivity is located on one side of the first isolation element, and a second conductive region on the opposite side of the first isolation element has the first conductivity, and is doped with ions and externally connected to a Ground voltage. In the semiconductor test structure described in item 1, when the well forms a joint with the well to clarify the cause of the leakage current at the joint part 3 · If you apply for the brother 20% joint 4 · If you apply for the second and simultaneous 5 · If you apply One step of the first separation element 6 · The semiconductor test structure described in the second item of the application, wherein the impurity region is separated from the first isolation element, and separate from the well shape 0 = the semiconductor test described in the second item of the range Structure, where: = the first isolation element is formed adjacently-the joint I /, and the well forms a joint. The semi-conductor described in the second item of the patent scope includes the plurality of first doped structures that are separated from each other, and is located between the doped regions with a second isolation element. . Interval. One of the semi-conducting devices described in Item 5 of the patent scope, the guard body must have a test structure, in which Page 13 ^ 20285 6. Scope of patent application 14 16 17 18: The semiconductor test structure described in item (1) of the scope of benefit, in which the electrical conductivity of the secondary V is opposite to the second conductivity. : ί The conductor test structure is used to clarify the cause of leakage current. The + conductor test structure includes: a ρ-type well; a first isolation element is located in the P-type well; ^ at least one N-type doped region is located in the first One side of the isolation element and-ρ = doped region is located in the well of the opposite side of the first isolation element = 51, the doping concentration of the ρ-type heavily doped region is greater than that of the 卩 -type opening and the external connection to A ground voltage. : Type Shen Λ # "The semiconductor test structure described in item 15 of the scope of interest. When the heterogeneous region is located in the P-type well, it forms an accessor CtlGn with the ρ-type well. The reason for the leakage current t is to apply for the semiconductor test structure described in item 16 of the patent scope. The ΪΛ heavy hybrid region is separated from the first isolation element, and is separate from the ρ-type t application. In the semiconductor test structure, the raw heavily doped region in the basin is adjacent to the first isolation element, and simultaneously forms a joint with the p-type well. 口 'Semiconductor clams as described in item 16 of the scope of patent application The trial combining step includes the plurality of N-type doped regions separated from each other. The second N-type doped regions are separated by a second isolation element; ㈣ = 19 1220285 Page 17