Protection ring structure and assembly structure
By adopting a multi-order contact protection ring structure in the gallium arsenide process, the problems of edge collapse and electric field dispersion of avalanche diodes are solved, effective concentration of the electric field and detection efficiency are improved, manufacturing costs are reduced, and component characteristics are improved.
Patent Information
- Application Number
- CN202310698630.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-13
- Publication Date
- 2024-12-13
AI Technical Summary
In the process of gallium arsenide, the edge collapses due to the electric field aggregation of zinc diffusion edges, resulting in increased dark counting rate, reduced collapse gain and worse timing error. The existing protection ring is not effective, especially when used alone. The protection ring cannot effectively disperse the electric field.
A two-step or multi-step contact protection ring structure is adopted, wherein the first contact protection ring is adjacent to the active area and the second contact protection ring is adjacent to the first ring, forming a stepped structure, and the third ring can be optionally arranged around the second ring, and is adjusted Annular height and width ratios are used to suppress edge collapse and electric field concentration.
Effectively suppress edge collapse, improve electric field concentration and detection efficiency, reduce manufacturing costs, and improve component characteristics. It is suitable for a variety of lidar and avalanche diode component structures, avoiding the use of floating protection rings.
Smart Images
Figure CN119133296A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a protection ring structure and a component structure, and in particular to a protection ring structure and a component structure with simple structure. Background Art
[0002] In the current process of growing indium gallium arsenide on indium phosphide (InGaAS / InP), if a planar avalanche diode is taken as an example, it will have a higher electric field concentration effect at the zinc diffusion edge and form edge collapse, which will cause the dark count rate (DCR) to increase, and its collapse gain will also decrease, and the timing error will also become worse. Therefore, the planar avalanche diode will use a guard ring to disperse the edge electric field to avoid edge collapse. However, there are many forms of guard rings, each with its own difficulty and effect in the process. Guard rings are divided into contact guard rings (attached guard ring, AGR) and floating guard rings (floating guard ring, FGR). If the contact guard ring is used alone, the electric field cannot be dispersed well. Summary of the invention
[0003] The technical problem to be solved by the present invention is to provide a protection ring structure suitable for an active area in view of the shortcomings of the prior art, and characterized in that the protection ring structure includes: a first contact protection ring, arranged around the active area; and a second contact protection ring, arranged around the first contact protection ring; wherein the first contact protection ring and the second contact protection ring are both contact protection rings, and the first contact protection ring and the second contact protection ring present a stepped structure.
[0004] Preferably, a height difference between the first contact guard ring and the active area is a first ring height, a height difference between the second contact guard ring and the first contact guard ring is a second ring height, and the first ring height and the second ring height are between 0.2um and 0.4um.
[0005] Preferably, the first contact protection ring includes a first annular width, the second contact protection ring includes a second annular width, and a ratio of a width value of the second annular width to a sum of the width values of the first annular width and the width values of the second annular width is greater than or equal to 0.25 and less than or equal to 0.5.
[0006] Preferably, the device further comprises a third contact protection ring, wherein the third contact protection ring is arranged around the second contact protection ring.
[0007] Preferably, a height difference between the third contact protection ring and the second contact protection ring is a third ring height, and the third ring height is between 0.2 um and 0.4 um.
[0008] Preferably, the third contact protection ring includes a third annular width, the ratio of the width value of the third annular width to the width value of the second annular width and the sum of the width values of the third annular width is greater than or equal to 0.25 and less than or equal to 0.5, and the first annular width is greater than or equal to 4um.
[0009] The present invention also discloses a component structure, characterized in that it at least includes: an active area; and a protection ring structure arranged around the active area, the protection ring structure includes multiple contact protection rings, and the multiple contact protection rings together present a stepped structure.
[0010] Preferably, the guard ring structure includes a first contact guard ring and a second contact guard ring, the first contact guard ring is arranged around the active area, and the second contact guard ring is arranged around the first contact guard ring.
[0011] Preferably, the guard ring structure further includes a third contact guard ring, and the third contact guard ring is arranged around the second contact guard ring.
[0012] One of the beneficial effects of the present invention is that the protection ring structure and component structure provided by the present invention utilize two or more contact protection rings of the same structure to effectively suppress edge collapse and make the electric field in the active area more concentrated, effectively improving detection efficiency and timing error. The protection ring structure of the present invention can be used in component structures of various laser radars and avalanche diodes. Since there is no need to use a floating protection ring, the contact protection ring is divided into two or a single contact protection ring is divided into two or more adjacent contact protection rings, which effectively reduces the area utilization rate, thereby effectively reducing the manufacturing cost and improving the component characteristics.
[0013] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 FIG. 4 is a schematic diagram of a guard ring structure according to a first embodiment of the present invention.
[0015] Figure 2 yes Figure 1 Schematic enlargement of region II.
[0016] Figure 3 is another schematic diagram of the guard ring structure according to the first embodiment of the present invention.
[0017] Figure 4 yes Figure 3 Schematic enlargement of region IV.
[0018] Figure 5A It is the electric field distribution diagram of a single contact guard ring.
[0019] Figure 5B yes Figure 1 Electric field distribution diagram of the guard ring structure.
[0020] Figure 5C yes Figure 3 Electric field distribution diagram of the guard ring structure.
[0021] Figure 6 is a schematic diagram of the component structure of the second embodiment of the present invention.
[0022] Figure 7 is another schematic diagram of the component structure of the second embodiment of the present invention. DETAILED DESCRIPTION
[0023] The following is an explanation of the implementation methods of the "protection ring structure and component structure" disclosed in the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted in actual size. It is stated in advance. The following embodiments will further explain the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention. In addition, the term "or" used in this article may include any one or more combinations of the associated listed items depending on the actual situation.
[0024] [First embodiment]
[0025] See also Figure 1 , Figure 2 , Figure 3 as well as Figure 4 , Figure 1 FIG. 4 is a schematic diagram of a guard ring structure according to a first embodiment of the present invention. Figure 2 yes Figure 1 Schematic enlargement of region II. Figure 3 is another schematic diagram of the guard ring structure according to the first embodiment of the present invention. Figure 4 yes Figure 3 Schematic enlargement of region IV.
[0026] See also Figure 1 , Figure 1 The device structure S1 includes a multi-layer structure, including an N-contact layer (N-contact), an indium phosphide substrate (InP substrate), an indium phosphide buffer layer (InP buffer), an indium gallium arsenide modulation layer (InGaAs absorption), an indium gallium arsenide phosphide gradient layer (InGaAsP grading), an indium phosphide charge layer (InP charge), an indium phosphide cap layer (InP cap), a diffusion layer (diffusion), a silicon nitride layer (SiNx), a P-contact layer (P-contact) and an active region coating layer (AR coating).
[0027] The diffusion layer (diffusion) uses phosphorus (P) and zinc (Zinc) as diffusion materials. In this embodiment, a guard ring structure GRS is provided, which is suitable for an active area CS1. The guard ring structure GRS includes a first contact guard ring AGR1 and a second contact guard ring AGR2. The schematic diagrams in this embodiment are all illustrated in the form of cross-sectional diagrams. In fact, each structure occupies a certain area, which may be circular, square or irregular, and is not limited in the present invention.
[0028] The first contact guard ring AGR1 and the second contact guard ring AGR2 are both attached guard rings (AGR). That is, the first contact guard ring AGR1 is arranged closely around the active area ARAR. The second contact guard ring AGR2 is arranged closely around the first contact guard ring AGR1. Structurally, since the first contact guard ring AGR1 and the second contact guard ring AGR2 have the same contact guard ring structure, the first contact guard ring AGR1 and the second contact guard ring AGR2 will present a stepped structure together.
[0029] See also Figure 1 as well as Figure 2 In this embodiment, if viewed from the overall circuit structure, a bottom reference point of the active region AR is relative to a high point of the overall device structure, and the active region AR includes an active region depth DAR. In this embodiment, the first contact guard ring AGR1 has a first contact guard ring depth D-AGR1 relative to the high point of the device structure. The second contact guard ring AGR2 has a second guard ring depth D-AGR2 relative to the high point of the device structure.
[0030] The second contact guard ring depth D-AGR2 is less than the first contact guard ring depth D-AGR1. The first contact guard ring depth D-AGR1 is less than the active region depth DAR.
[0031] See also Figure 2 , Figure 2 yes Figure 1 The area II is enlarged to show the area. The height difference between the first contact guard ring AGR1 and the active area AR is GH1. The width of the first contact guard ring AGR1 is the first ring width GW1. The height difference between the second contact guard ring AGR2 and the first contact guard ring AGR1 is GH2. The width of the second contact guard ring AGR2 is the second ring width GW2.
[0032] The height difference between the active area AR and the first contact guard ring AGR1 (first ring height GH1) and the height difference between the second contact guard ring AGR2 and the first contact guard ring AGR1 (second ring height) can be 0.2um-0.4um. The relationship between the first ring width GW1 and the second ring width GW2 can be shown in the following formula (1):
[0033] GW2 / (GW1+GW2)=25%~50%- Formula (1)
[0034] That is, the ratio of the width value of the second annular width GW2 to the sum of the width values of the first annular width GW1 and the second annular width GW is greater than or equal to 0.25 and less than or equal to 0.5.
[0035] In this embodiment, the width relationship between the first contact guard ring AGR1 and the second contact guard ring AGR2 is within the range of the above formula (1) (25% to 50%), which can significantly suppress the fringe electric field.
[0036] See also Figure 3 as well as Figure 4 , Figure 4 yes Figure 4 A schematic diagram showing an enlarged representation of region IV. Figure 1The component structure of the component structure S1', the protection ring structure GRS' of the component structure S1' also includes a third contact protection ring AGR3. The third contact protection ring AGR3 is arranged adjacent to the second contact protection ring AGR2. In the present embodiment, the adjacent arrangement means that no other semiconductor structure is arranged between the two protection rings. The third contact protection ring AGR3 includes a third annular width GW3. The relationship between the third annular width GW3 and the second annular width GW2 can be similar to the relationship between the second annular width GW2 and the first annular width GW1 described in the previous formula (1). Similarly, the height difference between the third contact protection ring AGR3 and the second contact protection ring AGR2 is the third annular height GH3. The third annular height GH3 can also be, for example, between 0.2um-0.4um. Furthermore, the first annular width GW1 is greater than or equal to 4um. The second annular width GW2 and the third annular width GW3 can meet the relationship of the aforementioned formula (1). In addition, the third contact protection ring AGR3 relative to the high point of the component structure will have a third protection ring depth D-AGR3. The third guard ring depth D-AGR3 is smaller than the second guard ring depth D-AGR2.
[0037] From another perspective, the multiple contact guard rings AGR1 - AGR2 or the multiple contact guard rings AGR1 - AGR3 in this embodiment are formed by etching a single-stage contact guard ring into a multi-stage contact guard ring.
[0038] See also Figure 5A , Figure 5B as well as Figure 5C . Figure 5A It is the electric field distribution diagram of a single contact guard ring. Figure 5B yes Figure 1 Electric field distribution diagram of the guard ring structure. Figure 5C yes Figure 3 The electric field distribution of the guard ring structure is shown in grayscale. Figure 5A This is the electric field distribution of a single contact guard ring. In the figure, it can be clearly seen that the edge electric field distribution in the area of the contact guard ring is relatively outward.
[0039] Figure 5B as well as Figure 5C Are used separately Figure 1 as well as Figure 2 Schematic diagram of the electric field distribution of the guard ring structure. Figure 5A Compared with the first-order guard ring of Figure 5B as well as Figure 5CThe electric field distribution is more concentrated in the middle area (active area AR), so the light response can be effectively improved. In addition, the guard ring structure (step-type contact guard ring, attached step guard ring, ASGR) of this embodiment can also suppress edge collapse. Moreover, the electric field in the middle area (active area AR) of this embodiment is more concentrated, which can also effectively improve the detection efficiency and timing error.
[0040] Furthermore, the guard ring structure GRS of the present embodiment is a stepped guard ring structure composed of multiple contact guard rings. Compared with the floating guard ring (FGR), the component area used in the guard ring structure GRS of the present embodiment is relatively small (the floating guard ring needs to be set at a certain distance). Therefore, a larger number of components can be produced on a substrate of the same area. In this way, the overall manufacturing cost can be reduced. In addition, the component structure S1 and the component structure S1' can be the main structure of the avalanche diode (APD). Since the component structure S1 and the component structure S1' of the present embodiment can effectively improve the characteristics of the avalanche diode, therefore, the avalanche diode with a stepped contact guard ring can become the main choice for the receiving end of laser radar and photon applications. That is, due to its good performance, it can improve the component characteristics and help the development of laser radar or photon-related applications.
[0041] [Second embodiment]
[0042] See also Figure 6 as well as Figure 7 , Figure 6 is a schematic diagram of the component structure of the second embodiment of the present invention. Figure 7 is another schematic diagram of the component structure of the second embodiment of the present invention.
[0043] In this embodiment, a device structure S2 and a device structure S3 are provided. The device structure S2 includes an active region AR and a guard ring structure GRS. Figure 7 The device structure S3 includes an active region and a guard ring structure GRS'. Similarly, the device structure S2 and the device structure S3 also include at least an N-contact layer (N-contact), an indium phosphide substrate (InP substrate), an indium phosphide buffer layer (InP buffer), an indium gallium arsenide modulation layer (InGaAs absorption), an indium gallium arsenide phosphide gradient layer (InGaAsP grading), an indium phosphide charge layer (InP charge), an indium phosphide cap layer (InP cap), a diffusion layer (diffusion), a silicon nitride layer (SiNx), a P-contact layer (P-contact) and an active region coating layer (AR coating) and other structures.
[0044] Similar to Figure 2 As shown, the guard ring structure GRS of the component structure S2 is arranged around the active area AR. The guard ring structure GRS includes a plurality of contact guard rings AGR1-AGR2. The plurality of contact guard rings AGR1-AGR2 together present a stepped structure. That is, the active area AR is at the lowest point, and the plurality of contact guard rings AGR1-AGR2 of the guard ring structure GRS gradually rise, presenting a multi-stage stepped structure. That is, although in Figure 6 Only two levels of contact guard rings AGR1-AGR2 are included. However, in fact, the number of contact guard rings included in the guard ring structure GRS can be adjusted according to actual needs. Figure 7 As shown in , the number of contact guard rings is 3. That is, in this embodiment, the number of contact guard rings included in the guard ring structures GRS and GRS' is N, where N is a natural number and is greater than or equal to 2. Furthermore, the contact guard rings AGR1-AGR2 in the guard ring structure GRS of this embodiment are all contact guard rings of the same structure.
[0045] See also Figure 7 , similar to Figure 4 As shown, the guard ring structure GRS' of the component structure S3 also includes a third contact guard ring AGR3. The third contact guard ring AGR3 is arranged around the second contact guard ring AGR2. Similarly, the third contact guard ring AGR3 and the first contact guard ring AGR1 and the second contact guard ring AGR2 are also contact guard rings (AGR) of the same structure. The first contact guard ring AGR1, the second contact guard ring AGR2 and the third contact guard ring AGR3 of the guard ring structure GRS also present a stepped structure that increases step by step.
[0046] The height difference between the active region AR and the first contact guard ring AGR1 (first ring height GH1) and the height difference between the second contact guard ring AGR2 and the first contact guard ring AGR1 (second ring height) can be 0.2um-0.4um. The relationship between the first ring width GW1 and the second ring width GW2 can be as shown in the above formula (1).
[0047] also, Figure 7 The height difference between the third contact guard ring AGR3 and the second contact guard ring AGR2 can also be set in the range of 0.2um-0.4um. Furthermore, the relationship between the third annular width GW3 and the second annular width of the third contact guard ring AGR3 can also be shown as the above formula (1).
[0048] The active area AR can be the main component structure of a laser radar (Light Detection And Ranging, LIDAR), an avalanche diode (APD) or a photon-related application. That is, the component structure S2 and the component structure S3 can be the main structure of the avalanche diode (APD). Since the component structure S2 and the component structure S3 of this embodiment can effectively improve the characteristics of the avalanche diode, the avalanche diode with a stepped contact protection ring can become the main choice for the receiving end of laser radar and photon applications. That is, due to its good performance, it can improve the component characteristics and help the development of laser radar or photon-related applications.
[0049] [Beneficial Effects of Embodiments]
[0050] One of the beneficial effects of the present invention is that the protection ring structure and component structure provided by the present invention utilize two or more contact protection rings of the same structure to effectively suppress edge collapse and make the electric field in the active area more concentrated, effectively improving detection efficiency and timing error. The protection ring structure of the present invention can be used in component structures of various laser radars and avalanche diodes. Since there is no need to use a floating protection ring, the contact protection ring is divided into two or a single contact protection ring is divided into two or more adjacent contact protection rings, which effectively reduces the area utilization rate, thereby effectively reducing the manufacturing cost and improving the component characteristics.
[0051] The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the scope of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention's specification and drawings are included in the scope of the present invention.
Claims
1. A guard ring structure, applicable to an active area, characterized in that: The protection ring structure comprises: a first contact protection ring, disposed around the active region; and a second contact protection ring, arranged around the first contact protection ring; The first contact protection ring and the second contact protection ring are both contact protection rings, and the first contact protection ring and the second contact protection ring present a stepped structure.
2. The protection ring structure according to claim 1, characterized in that: A height difference between the first contact guard ring and the active region is a first ring height, a height difference between the second contact guard ring and the first contact guard ring is a second ring height, and the first ring height and the second ring height are between 0.2um and 0.4um.
3. The protection ring structure according to claim 1, characterized in that: The first contact protection ring includes a first annular width, the second contact protection ring includes a second annular width, and a ratio of a width value of the second annular width to a sum of the width values of the first annular width and the width values of the second annular width is greater than or equal to 0.25 and less than or equal to 0.
5.
4. The protection ring structure according to claim 3, characterized in that: The device further comprises a third contact protection ring, wherein the third contact protection ring is arranged around the second contact protection ring.
5. The protection ring structure according to claim 4, characterized in that: A height difference between the third contact guard ring and the second contact guard ring is a third ring height, and the third ring height is between 0.2 um and 0.4 um.
6. The protection ring structure according to claim 5, characterized in that: The third contact protection ring includes a third annular width, and the ratio of the width value of the third annular width to the width value of the second annular width and the sum of the width values of the third annular width is greater than or equal to 0.25 and less than or equal to 0.5, and the first annular width is greater than or equal to 4um.
7. A component structure, characterized in that: At least: One active area; as well as A guard ring structure is arranged around the active area, and the guard ring structure includes a plurality of contact guard rings, and the plurality of contact guard rings together present a stepped structure.
8. The assembly structure according to claim 7, characterized in that: The guard ring structure includes a first contact guard ring and a second contact guard ring. The first contact guard ring is arranged around the active region, and the second contact guard ring is arranged around the first contact guard ring.
9. The assembly structure according to claim 8, characterized in that: The guard ring structure further includes a third contact guard ring, and the third contact guard ring is arranged around the second contact guard ring.