TWI491057B - Avalanche photodiode fabricating method and photo mask thereof - Google Patents

Description

Process method for accumulating collapse light diode and reticle device thereof

The invention relates to a process method for accumulating collapsing light diodes and a reticle device thereof, and more particularly to an self-alignment process in a diffusion process of accumulating crash light diodes by an innovative pattern design of a reticle device An effect of a method of increasing the collapse of a photodiode and a reticle device thereof.

Avalanche Photodiode (APD) is a photosensitive element that converts optical signals into electronic signals. The function of the APD is similar to that of a conventional conventional photodiode, both of which convert light energy into an electronic signal. However, APD provides higher sensitivity due to its internal gain mechanism. Briefly, in a typical conventional p-i-n photodiode, a single photon can be converted into an electron-hole pair; in APD, a single photon can be absorbed to form multiple electron-hole pairs. Therefore, the application of APD has been widely recognized in the field of optoelectronic technology in recent years.

As shown in FIG. 1 , it is a schematic diagram of a simplified planar trapped light-emitting diode (APD) profile structure. In the APD which generally defines the cumulative collapse region in a diffusion manner, three main diffusion defining regions are formed on the surface of an n-type InP substrate 11 by p-conductive impurities, respectively, which are the outer ring protection ring 21 (Guard Ring), intermediate first diffusion region 22 (or may be referred to as active conductive region), inner deep diffusion region 23 (or may be referred to as repeated diffusion region), and boundary region not shown in the figure and many more. As shown in FIG. 2A, in the conventional technology, the guard ring 21 and the first diffusion region 22 can be simultaneously defined in the same diffusion process by the same first photomask 31. As for the deep diffusion region 23, it is defined in the second diffusion process by the second mask 32 as shown in Fig. 2B.

Obviously, as can be seen from FIG. 1, the deep diffusion region 23 and the first diffusion region 22 need to be precisely aligned. However, there must be errors in the alignment process, and this error may seriously affect the performance of the APD components. This phenomenon can also be found in the electric field simulation as shown in Figure 3. When the optical windows of the first and second reticle 31, 32 used for the first and second diffusions produce alignment errors (especially the light window and the second of the first diffusion region 22 of the first reticle 31) The optical window of the deep diffusion region 23 of the reticle 32 has a more serious edge collapse phenomenon and a phenomenon in which the gains of the two sides are not equal, and the magnitude of the electric field is logarithmically related to the component gain, so that a slightly uneven electric field distribution may result in Severe gain drop. As shown in FIG. 4A and FIG. 4B, by measuring the optical responsiveness of the APD having the alignment error of 1~2 μm by the lens fiber along the x-axis direction (ie, the horizontal direction) indicated in FIG. In Figure 4A, it is found that the active region gain is not flat and the collapse in Figure 4B is found at the edge of the active region and the degree of left and right is different. The situation is even worse, which causes the center gain and the breakdown voltage to drop, and needs to be improved.

The main object of the present invention is to provide a process for accumulating a collapsed light diode (APD) and a reticle device thereof, which can provide a self-aligning effect in a diffusion process by an innovative pattern design of the reticle device. In order to improve the component process yield and characteristic uniformity of the cumulative crash LED.

In order to achieve the above object, the present invention provides a process for accumulating a collapsed photodiode by performing a diffusion process on a substrate for fabricating a cumulative collapse photodiode to form at least: a first diffusion region a guard ring and a deep diffusion region overlapping the center of the first diffusion region. In this diffusion procedure, a unique reticle device is used to achieve self-alignment. The reticle device includes a first reticle and a second reticle, respectively defining a first pattern and a second pattern on the substrate, and performing the diffusion process according to the first pattern and the second pattern To form the deep diffusion region, the first diffusion region, and the guard ring. The first pattern defined by the first reticle includes at least one permeable light-transmitting portion from the inner to the outer surface: a first diffusion ring region located at the center and having an outer diameter of one of the repeating diffusion regions D2 and an outer diameter D1 And a guard ring area with an outer diameter of DG. At the same time, the first pattern is opaque: one of the width w1, the first barrier ring is located between the repeating diffusion zone and the first diffusion ring zone, and the width of the second barrier ring is located at the second barrier ring. Between the first diffusion ring zone and the guard ring zone. Moreover, the second pattern defined by the second mask comprises at least one of a second diffusion region located at the center and having an outer diameter D2a. Wherein, the outer diameter of the deep diffusion region is defined by the outer diameter D2 of the repeated diffusion region, and the outer diameter of the first diffusion region is defined by the outer diameter D1 of the first diffusion ring region, and the protection ring The outer diameter is defined by the outer diameter DG of the guard ring zone. In addition, DG>D1>D2a>D2.

In a preferred embodiment, when the alignment error value (ie, the center offset) of the two patterns formed by the two masks in the diffusion process is De, then w1≧De; and (D2+ 2w1) ≧ (D2a+De).

In a preferred embodiment, 1 μm ≦ w1 ≦ 5 μm; 10 μm ≦ (D1-D2) ≦ 30 μm; and 1 μm ≦ (D2a-D2) ≦ 5 μm.

In a preferred embodiment, the diffusion process is a conventional diffusion process and includes the following steps:

(A) forming a first dielectric layer on the substrate;

(B) defining the first dielectric layer by the first photomask;

(C) removing a portion of the first dielectric layer of the light permeable portion;

(D) performing a first shallow diffusion of the substrate with a conductive material, and forming at least one electrically conductive diffusion layer on a region of the substrate that is not covered by the first dielectric layer; wherein the diffusion layer is repeatedly diffused The region and the first diffusion ring region are fused together laterally at a region corresponding to the first barrier ring;

(E) forming a second dielectric layer on the first dielectric layer and the conductive region;

(F) defining the second dielectric layer by the second photomask;

(G) removing a portion of the second dielectric layer of the light permeable portion;

(H) performing a second shallow diffusion of the substrate with a conductive material, and forming the deep diffusion region in a region of the substrate that is not covered by the second dielectric layer.

Preferably, the substrate is an n-type InP substrate, or a substrate composed of GaAs, Si, GaN or the like; the first dielectric layer is made of tantalum nitride (Si ₃ N ₄ ); The conductive material is bismuth ion (Be) or zinc (Zn); the second dielectric value is cerium oxide (SiO ₂ ).

In another embodiment, the diffusion process is an inverse diffusion process and includes the following steps:

(A) forming a first dielectric layer on the substrate;

(B) defining the first dielectric layer by the first photomask;

(C) removing a portion of the first dielectric layer of the light permeable portion;

(D) forming a second dielectric layer on the substrate;

(E) defining the second dielectric layer by the second photomask;

(F) removing a portion of the second dielectric layer of the light permeable portion;

(G) performing a first shallow diffusion of the substrate with a conductive material, and forming at least one electrically conductive diffusion layer on a region of the substrate that is not covered by the second dielectric layer;

(H) removing the entire surface of the second dielectric layer on the substrate;

(I) defining the second pattern on the substrate and the first dielectric layer by using a second mask and a photoresist;

(J) removing the first dielectric layer at the first barrier ring by solution side etching, and then removing the photoresist material;

(K) Conducting a second shallow diffusion of the substrate with a conductive material.

In still another embodiment, the diffusion process is a wet etch followed by a diffusion process and includes the following steps:

(A) forming a first dielectric layer on the substrate;

(B) defining the first dielectric layer by the first photomask;

(C) removing a portion of the first dielectric layer of the light permeable portion;

(D) forming a second dielectric layer on the substrate;

(E) defining the second dielectric layer by the second photomask;

(F) removing a portion of the second dielectric layer of the light permeable portion;

(G) wet etching the substrate such that the substrate regions not covered by the first and second dielectric layers are etched to form a recessed region;

(H) removing the entire surface of the second dielectric layer on the substrate;

(I) defining the second pattern on the substrate and the first dielectric layer by using a second mask and a photoresist;

(J) removing the first dielectric layer at the first barrier ring of the permeable portion by solution side etching, and then removing the photoresist material;

(K) subjecting the substrate to a shallow diffusion process with a conductive material, without being covered by the first dielectric layer on the substrate and forming a region of the recessed region to form at least one electrically conductive diffusion layer.

The method of the method for accumulating collapsed light diode (APD) of the present invention and the main principle of the reticle device are to define all the light windows to be defined in the first reticle, and then in the reticle The required portion is taken out and the unnecessary portion is masked, so that the relative spacing of all the light windows is defined by the mask at the beginning without an alignment error. This technique can be applied to a conventional diffusion process (traditional diffusion) in which a large-area shallow diffusion is defined and then a small-area deep diffusion is defined. It can also be applied to first define a small-area diffusion and then to spread a large area (opposite diffusion), or After the small-area light window is etched to develop a deep and shallow drop, and then a single diffusion (diffusion after wet etching) is performed, the present invention can be said to have a very high application range.

In order to more clearly describe the method of manufacturing the APD of the present invention and the reticle apparatus thereof, the following will be described in detail in conjunction with the drawings.

Referring to FIG. 5A and FIG. 5B, a preferred embodiment of the reticle device used in the diffusion process of the APD process method of the present invention includes a first reticle 41 and a second reticle 42. The first and second masks 41 and 42 define a first diffusion region 22, a guard ring 21, and a center of the first diffusion region 22 as shown in FIG. 1 on the substrate for fabricating the APD 10. The deep diffusion region 23, and the outermost boundary region and the like.

Taking a typical APD 10 as an example, the substrate 11 is usually an n-type InP substrate or a substrate made of GaAs, Si, GaN or the like, which can be divided into: One of the bottommost side is an n-electrode 111, an n ⁺ InP substrate layer 112, an n ^- InGaAs light absorbing layer 113, an nInP electric field layer 114, and an n ^- InP window layer 115. The first diffusion region 22, the guard ring 21, and the deep diffusion region 23 are located in the window layer 115. In some conventional examples, an nInP buffer layer (not shown) is also often disposed between the substrate layer 112 and the light absorbing layer 113, and an InGaAsP migration layer is disposed between the light absorbing layer 113 and the electric field layer 114 ( Not shown in the figure). Since the typical APD 10 structure described herein is a conventional one and is not a technical feature of the present invention, it will not be described again.

As shown in FIG. 5A and FIG. 5B, the first mask 41 and the second mask 42 of the present invention respectively define a first pattern and a second pattern on the upper surface of the substrate 11, and according to the first A pattern and a second pattern perform a diffusion process to form the deep diffusion region 23, the first diffusion region 22, and the guard ring 21. As shown in FIG. 5A, the first pattern defined by the first mask includes at least one of light transmissive from the inside to the outside: one of the repeating diffusion regions 411 at the center and having an outer diameter D2, and an outer diameter D1. The first diffusion ring region 412 and the outer diameter DG are one of the guard ring regions 413. Meanwhile, the first pattern is opaque: one of the widths w1, the first barrier ring 414 is located between the repeating diffusion region 411 and the first diffusion ring region 412, and the second barrier ring is one of the widths w2. 415 is located between the first diffusion ring region 412 and the guard ring region 413. As shown in FIG. 5B, the second pattern defined by the second mask 42 includes at least one of a second diffusion region 421 located at the center and having an outer diameter D2a. The outer diameter and coverage of the deep diffusion region 23 are defined by the outer diameter D2 of the repeated diffusion region 411, and the outer diameter of the first diffusion region 22 is determined by the outer diameter D1 of the first diffusion ring region 412. The outer diameter of the guard ring 21 is defined by the outer diameter DG of the guard ring region 413. In addition, DG>D1>D2a>D2.

Next, the structural difference between the photomask device used in the present invention and the conventional photomask is compared. The first photomask 31 of the present invention shown in FIG. 5A is compared with the first photomask 31 of the prior art shown in FIG. 2A. The first photomask 31 of the prior art has two light transmissive regions, respectively It is an inner circle and an outer ring, wherein the inner circle is used to define a first diffusion zone 22 having a diameter D1, and the outer ring is used to define a guard ring 21 having an outer diameter DG. In the reticle device of the present invention, a ring is formed between the first diffusion ring region 412 (outer diameter D1) of the first reticle 41 and the repeated diffusion region 411 (outer diameter D2). The first barrier ring 414 having a width w1 is an opaque region, and the region of the opaque first barrier ring 414 is an alignment error region that can be tolerated for automatic alignment. As for the innermost circle (second diffusion region 421) of the first mask 41 of the present invention, the size of the circle in the second mask 21 of the prior art is the same, and is used to define the deep diffusion of the outer diameter D1. District 23. That is, in the present invention, when the second mask 42 is aligned, the alignment error is as long as it falls within the range of the first barrier ring 414 of the first mask 41 that is opaque, so that the first diffusion can be achieved. There is no deviation from the second diffusion. Because when the second diffusion process is finally performed, the area of the substrate exposed to the outside is still the inner circle repeating diffusion region 411 which is already defined by the first mask 41 in the first mask process, and the repeated diffusion The size of the circle in the second reticle of zone 411 and conventional technology is generally D2. Therefore, the outer diameter of the second diffusion region 421 defined by the second reticle 42 of the present invention is slightly larger than the outer diameter of the deep diffusion region 23 defined by the second reticle 31 of the prior art, and is not intended to be defined. The size of the deep diffusion region 23, but to ensure that the second diffusion region 421 falls within the region of the first barrier ring 414 that has been defined by the first mask 41 of the present invention, while making the first A repeating diffusion region 411, which has been defined by a mask 41, is exposed to perform a diffusion process to constitute the deep diffusion region 23. It can be seen that the size of the second diffusion region 421 of the present invention and the size of the first barrier ring 414 need to be properly defined to ensure self-alignment can be achieved within the alignment error range. In this embodiment, if the alignment error value (ie, the center offset) of the two patterns formed by the two masks in the diffusion process is De, the width of the first barrier ring 414 should be greater than the The error value, that is, w1≧De; at the same time, and the second diffusion region 421 should fall within the outer diameter of the first barrier ring 414 after the offset value of De, that is, (D2+2w1)≧(D2a+De ). However, the width of the first barrier ring 414 should not be too large, otherwise it will be compressed to the width of the first diffusion ring region 412. Secondly, it will be more difficult to achieve lateral diffusion during the thermal diffusion process, so that the repeated diffusion region 411 is laterally expanded. The result of fusion with the first diffusion ring region 412 (detailed later). Therefore, in a preferred embodiment of the present invention, the width w1 of the first barrier ring 414 is preferably 1 μm ≦ w1 ≦ 5 μm; at the same time, 10 μm D (D1-D2) ≦ 30 μm; and 1 μm ≦ (D2a- D2) ≦ 5 μm is preferred.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Several preferred embodiments of the reticle device of the present invention for application to the diffusion process in the collapsed photodiode process will be specifically described below.

Please refer to FIG. 6A to FIG. 6H, which is a first preferred embodiment of the conventional diffusion process of the photomask device of the present invention applied to accumulate crash LEDs. In the first preferred embodiment, the diffusion program includes the following steps:

(A) As shown in FIG. 6A, a first dielectric layer 61 is formed on the surface of the n-type InP substrate 60. In this embodiment, the material of the first dielectric layer 61 may be tantalum nitride (Si ₃ N ₄ ) and is preferably formed by a deposition process.

(B) As shown in FIG. 6B, the first pattern 62 is defined by the first dielectric layer 61 by the first mask 41 and the photoresist process as shown in FIG. The first pattern 62 includes a light transmissive repeating diffusion region 621, a non-transmissive first blocking ring 622, a light transmissive first diffusion ring region 623, and a non-transparent second portion. A barrier ring 624 and a light-permeable guard ring region 625.

(C) As shown in FIG. 6C, the first dielectric layer 61 which is permeable to light (that is, exposed to the outside) is partially removed by a wet etching or dry etching process of Si ₃ N ₄ .

(D) As shown in FIG. 6D, the substrate 60 is firstly shallowly diffused with a conductive material, and at least a region of the substrate 60 not covered by the first dielectric layer 61 forms at least one conductive diffusion. Layer 63. In this embodiment, the conductive material may be bismuth ion (Be) or zinc (Zn), and the first shallow diffusion process may be a thermal diffusion process. Wherein, in the process of thermal diffusion, not only in the longitudinal direction but also in the lateral direction, the diffusion time can be controlled, so that the specific diffusion time can be controlled so that the repeated diffusion region 621a is merged with the first diffusion ring region 623a due to side expansion. together. In other words, the diffusion layer 63 is fused together in the lateral direction with respect to the first barrier ring 622a in the repeated diffusion region 621a and the first diffusion ring region 623a; and because the guard ring 625a and the first diffusion ring region 623a The spacing is relatively long (that is, the width w2 of the second blocking ring 624a is large) and does not fuse together.

(E) As shown in FIG. 6E, a second dielectric layer 64 is formed on the first dielectric layer 61 and the conductive region 63. The material of the second dielectric layer 64 may be cerium oxide (SiO ₂ ) and is preferably formed by a deposition process.

(F) The second dielectric layer 64 is defined by the second photomask 64 by the second mask 42 as shown in FIG. The second pattern 65 includes a second diffusible region 651 that is transparent to light.

(G) As shown in FIG. 6G, the second dielectric layer 64 of the light transmissive portion is partially removed by a wet etching or dry etching process of SiO ₂ . In this step, since the etching process has different etching rates for both SiO ₂ and Si ₃ N ₄ , the SiO ₂ film is etched away, but the underlying Si ₃ N ₄ film still exists and the light exposed to the outside is formed. The window is still the repeating diffusion zone 621a defined by the first reticle.

(H) performing a second diffusion of the substrate 60 with the conductive material as described above, and forming a deep diffusion region on the substrate 60 without the region covered by the second dielectric layer 64 and the first dielectric layer 61. 65.

Referring to FIG. 7 , in the plurality of APDs produced by using the photomask device and the processing method of the present invention, two APD components are randomly selected for optical response measurement according to FIG. 4A and FIG. 4B. Graph. It can be found from FIG. 7 that the two APD components fabricated by the photomask device of the present invention and the process method have almost the same photoresponse characteristics, and the gain unevenness or edge collapse as shown in FIG. 4A or FIG. 4B does not occur. The effect. It can be seen that the present invention can solve the problems encountered in the conventional conventional processes mentioned above, and greatly improve the process yield and economic benefit of the components.

In the other preferred embodiments of the present invention, the same elements and structures will be given the same names and numbers, and will not be described again.

Referring to FIG. 8A to FIG. 8K, an embodiment of the photomask device of the present invention applied to the opposite diffusion process of the cumulative collapse photodiode is shown. In this embodiment, the diffusion program includes the following steps:

(A) A first dielectric layer 81 is formed on the substrate 80 as shown in FIG.

(B) As shown in FIG. 8B, the first dielectric layer 81 is defined by the first photomask 81 by the first photomask 41.

(C) As shown in Fig. 8C, the first dielectric layer 81 of the light permeable portion is partially removed.

(D) A second dielectric layer 83 is formed on the substrate 80 as shown in FIG.

(E) As shown in FIG. 8E, the second dielectric layer 83 is defined by the second photomask 83 by the second mask 42.

(F) As shown in Fig. 8F, the second dielectric layer 83 of the light permeable portion is partially removed.

(G) As shown in FIG. 8G, the substrate 80 is first diffused with a conductive material, and the region of the substrate 80 not covered by the second dielectric layer 83 forms at least one conductive diffusion. Layer 85.

(H) As shown in FIG. 8H, the second dielectric layer 83 on the substrate 80 is removed over the entire surface.

(I) As shown in FIG. 8I, the second pattern 84a is defined on the substrate 80 and the first dielectric layer 81 by the second mask 42 and a photoresist.

(J) As shown in FIG. 8J, the first dielectric layer 81 at the first barrier ring is removed by solution side etching, and then the photoresist material is removed.

(K) As shown in FIG. 8K, the substrate 80 is subjected to a second large-area shallow diffusion with a conductive material.

Please refer to FIG. 8A to FIG. 8K , which are embodiments of the etch mask device of the present invention applied to the first wet etch diffusion process of the cumulative collapse photodiode. In this embodiment, the diffusion program includes the following steps:

(A) A first dielectric layer 91 is formed on the substrate 90 as shown in FIG.

(B) As shown in FIG. 9B, the first dielectric layer 91 defines the first pattern 92 by the first mask 41.

(C) As shown in FIG. 9C, the first dielectric layer 91 of the light permeable portion is partially removed.

(D) A second dielectric layer 93 is formed on the substrate 90 as shown in FIG.

(E) As shown in FIG. 9E, the second dielectric layer 93 defines the second pattern 94 by the second mask 42.

(F) As shown in FIG. 9F, the second dielectric layer 93 of the light permeable portion is partially removed.

(G) As shown in FIG. 9G, the substrate 90 is wet etched such that the substrate regions not covered by the first and second dielectric layers 91, 93 are etched to form a recessed region 95.

(H) As shown in FIG. 9H, the second dielectric layer 93 on the substrate 90 is removed over the entire surface.

(I) As shown in FIG. 9I, the second pattern 94a is defined on the substrate 90 and the first dielectric layer 91 by the second mask 42 and a photoresist.

(J) As shown in FIG. 9J, the first dielectric layer 91 at the first barrier ring of the light-permeable portion is removed by solution side etching, and then the photoresist material is removed.

(K) As shown in FIG. 9K, the substrate 90 is subjected to a single shallow diffusion process with a conductive material, and is not covered by the first dielectric layer 91 on the substrate 90 and the region of the recessed region 95 is formed. At least one electrically conductive diffusion layer 96.

The above-mentioned embodiments are not intended to limit the scope of application of the present invention, and the scope of the present invention should be based on the technical spirit defined by the content of the patent application scope of the present invention and the scope thereof. It is to be understood that the scope of the present invention is not limited by the spirit and scope of the present invention, and should be considered as a further embodiment of the present invention.

10‧‧‧APD

11‧‧‧Substrate

111‧‧‧Electrode

112‧‧‧ substrate layer

113‧‧‧Light absorbing layer

114‧‧‧ electric field layer

115‧‧‧ window layer

21‧‧‧Protection ring

22‧‧‧First Diffusion Zone

23‧‧‧Deep diffusion zone

31‧‧‧First mask

32‧‧‧second mask

41‧‧‧First mask

411‧‧‧Repetitive diffusion zone

412‧‧‧First Diffusion Zone

413‧‧‧Protection area

414‧‧‧First barrier ring

415‧‧‧second barrier ring

42‧‧‧second mask

421‧‧‧Second diffusion zone

60, 80, 90‧‧‧ substrates

61, 81, 91‧‧‧ first dielectric layer

62, 82, 92‧‧‧ first pattern

621, 621a‧‧‧ Repeated diffusion zone

622, 622a‧‧‧ first barrier ring

623, 623a‧‧‧First Diffusion Zone

624, 624a‧‧‧ second barrier ring

625, 625a‧‧‧protected ring area

63, 85, 96‧‧ ‧ diffusion layer

64, 83, 93‧‧‧ second dielectric layer

65, 84, 84a, 94, 94a‧‧‧ second pattern

651‧‧‧Second diffusion zone

95‧‧‧ recessed area

Figure 1 is a simplified schematic diagram of a cross-sectional structure of a conventional collapsed photodiode (APD).

Figure 2A is a schematic illustration of a pattern defined by a first reticle of the prior art.

Figure 2B is a schematic illustration of a pattern defined by a second reticle of the prior art.

Figure 3 is a prior art APD with an electric field simulation plot of alignment and error in the first and second masks.

Figure 4A is an example 1 of the optical response profile of the APD of the first and second mask alignment errors of the prior art (the active region gain is not flat).

Figure 4B is an example 2 of the optical response profile of the APD for the first and second mask alignment errors of the prior art (the active region edge is severely collapsed).

Figure 5A is a schematic illustration of the pattern defined by the first mask in the mask assembly used in the APD process of the present invention.

Figure 5B is a schematic illustration of the pattern defined by the second mask in the mask assembly used in the APD process of the present invention.

6A to 6H disclose a first preferred embodiment (traditional diffusion process) of the APD process method of the present invention.

FIG. 7 is a graph obtained by performing optical response measurement on two APD elements produced by the APD process method of the present invention.

8A to 8K disclose a second preferred embodiment of the APD process method of the present invention (opposite diffusion process).

9A to 9K disclose a third preferred embodiment of the APD process method of the present invention (first wet etching process).

41. . . First mask

411. . . Repeated diffusion zone

412. . . First diffusion zone

413. . . Protection ring

414. . . First barrier ring

415. . . Second barrier ring

42. . . Second mask

421. . . Second diffusion zone

Claims (11)

A process for accumulating a collapsed photodiode is performed by performing a diffusion process on a substrate for fabricating a cumulative collapse photodiode to form at least: a guard ring on the outer ring, and a middle portion a diffusion region and a deep diffusion region overlapping the center of the first diffusion region; in the diffusion process, a first photomask and a second photomask are used to define the substrate by a photoresist material Forming a first pattern and a second pattern, and performing the diffusion process according to the first pattern and the second pattern to form the deep diffusion region, the first diffusion region, and the guard ring; wherein, by the first mask The first pattern defined includes at least a light transmissive portion from the inner to the outer side: a repeating diffusion region located at the center and having an outer diameter D2, a first diffusion ring region having an outer diameter D1, and a guard ring having an outer diameter of DG At the same time, the first pattern is opaque: one of the width w1, the first barrier ring is located between the repeating diffusion region and the first diffusion ring region, and the second barrier ring is one of the width w2 Located in the first diffusion ring zone and protected Between the ring regions; and, the second pattern defined by the second reticle includes at least one of permeable to light: a second diffusion region at the center and having an outer diameter D2a; wherein, outside the deep diffusion region The diameter system is defined by the outer diameter D2 of the repeating diffusion zone, the outer diameter of the first diffusion zone is defined by the outer diameter D1 of the first diffusion ring zone, and the outer diameter of the guard ring is protected by the guard ring zone. The outer diameter DG is defined; in addition, DG>D1>D2a>D2; wherein, when the alignment error value (that is, the center offset) of the two patterns formed by the two masks in the diffusion process is De , then w1≧De; and (D2+2w1)≧(D2a+De); Wherein the diffusion process comprises the steps of: (A) forming a first dielectric layer on the substrate; (B) defining the first dielectric layer with the photoresist by the first photomask Out of the first pattern; (C) removing the first dielectric layer portion of the light permeable portion; (D) performing a first shallow diffusion of the substrate with a conductive material, and not being first on the substrate The region covered by the dielectric layer forms at least one electrically conductive diffusion layer; wherein the diffusion layer is fused to the first diffusion ring region laterally at a region corresponding to the first barrier ring in the repeated diffusion region; (E) Forming a second dielectric layer on the first dielectric layer and the conductive region; (F) defining the second dielectric layer by the second photomask with the photoresist material; (G) Removing a portion of the second dielectric layer of the light permeable portion; (H) performing a second shallow diffusion of the substrate with a conductive material, and forming the deep layer on a region of the substrate that is not covered by the second dielectric layer Diffusion zone. The method for manufacturing a cumulative collapse photodiode according to claim 1, wherein the substrate is an n-type InP substrate or a substrate composed of GaAs, Si, or GaN material. The material of the first dielectric layer is tantalum nitride (Si ₃ N ₄ ); the conductive material is bismuth ion (Be) or zinc (Zn); the second dielectric value is cerium oxide (SiO ₂ ) . The method for manufacturing a cumulative collapse photodiode according to claim 1, wherein the method of forming the first dielectric layer and the second dielectric layer is a deposition process; and removing the first component of the permeable portion The electrical layer is one of the following: a wet etching process, and a dry etching process; and, the first And the second shallow diffusion process is a thermal diffusion process; wherein, 1 μm ≦ w1 ≦ 5 μm; 10 μm ≦ (D1-D2) ≦ 30 μm; and 1 μm ≦ (D2a-D2) ≦ 5 μm. A process for accumulating a collapsed photodiode is performed by performing a diffusion process on a substrate for fabricating a cumulative collapse photodiode to form at least: a guard ring on the outer ring, and a middle portion a diffusion region and a deep diffusion region overlapping the center of the first diffusion region; in the diffusion process, a first photomask and a second photomask are used to define the substrate by a photoresist material Forming a first pattern and a second pattern, and performing the diffusion process according to the first pattern and the second pattern to form the deep diffusion region, the first diffusion region, and the guard ring; wherein, by the first mask The first pattern defined includes at least a light transmissive portion from the inner to the outer side: a repeating diffusion region located at the center and having an outer diameter D2, a first diffusion ring region having an outer diameter D1, and a guard ring having an outer diameter of DG At the same time, the first pattern is opaque: one of the width w1, the first barrier ring is located between the repeating diffusion region and the first diffusion ring region, and the second barrier ring is one of the width w2 Located in the first diffusion ring zone and protected Between the ring regions; and, the second pattern defined by the second reticle includes at least one of permeable to light: a second diffusion region at the center and having an outer diameter D2a; wherein, outside the deep diffusion region The diameter system is defined by the outer diameter D2 of the repeating diffusion zone, the outer diameter of the first diffusion zone is defined by the outer diameter D1 of the first diffusion ring zone, and the outer diameter of the guard ring is protected by the guard ring zone. Defined by the outer diameter DG; in addition, DG>D1>D2a>D2; wherein, the pair of two patterns formed by the two masks in the diffusion process When the quasi-error value (that is, the center offset) is De, then w1≧De; and (D2+2w1)≧(D2a+De); wherein the diffusion procedure is an inverse diffusion process which includes the following steps: A) forming a first dielectric layer on the substrate; (B) defining the first dielectric layer with the photoresist material by the first photomask; (C) is transparent Removing a first dielectric layer of the light portion; (D) forming a second dielectric layer on the substrate; (E) defining the second dielectric layer with the photoresist material by the second photomask Deleting the second pattern; (F) removing the second dielectric layer portion of the light permeable portion; (G) performing a first shallow diffusion of the substrate with a conductive material, and not being second for the substrate The region covered by the dielectric layer forms at least one electrically conductive diffusion layer; (H) the entire dielectric layer on the substrate is removed; (I) the second photomask and the photoresist material are on the substrate And defining the second pattern on the first dielectric layer; (J) removing the first dielectric layer at the first barrier ring by solution side etching, and then removing the photoresist material; (K) using a conductive material Performing a second shallow diffusion on the substrate The method for processing a cumulative collapse photodiode according to claim 4, wherein the substrate is an n-type InP substrate or a substrate composed of GaAs, Si, or GaN material. The material of the first dielectric layer is tantalum nitride (Si ₃ N ₄ ); the conductive material is bismuth ion (Be) or zinc (Zn); the second dielectric value is cerium oxide (SiO ₂ ) . The method for fabricating a collapsed photodiode according to claim 4, wherein the method of forming the first dielectric layer and the second dielectric layer is a deposition process; and removing the first component of the permeable portion The electrical layer is one of the following: a wet etching process, and a dry etching process; and, the first and second shallow diffusion processes are thermal diffusion processes; wherein, 1 μm ≦ w1 ≦ 5 μm; 10 μm ≦ (D1- D2) ≦ 30 μm; and 1 μm ≦ (D2a-D2) ≦ 5 μm. A process for accumulating a collapsed photodiode, wherein a diffusion process is performed on a substrate for fabricating a cumulative collapse photodiode to form at least: a guard ring on the outer ring, in between a first diffusion region and a deep diffusion region overlapping the center of the first diffusion region; in the diffusion process, the first photomask and a second photomask are used to treat the substrate with a photoresist material Determining a first pattern and a second pattern respectively, and performing the diffusion process according to the first pattern and the second pattern to form the deep diffusion region, the first diffusion region, and the guard ring; wherein the first light is The first pattern defined by the cover includes at least one of light transmissive from the inside to the outside: a repeating diffusion zone located at the center and having an outer diameter D2, a first diffusion ring zone having an outer diameter D1, and one of the outer diameters DG Protecting the ring region; at the same time, the first pattern is opaque: one of the width w1, the first barrier ring is located between the repeating diffusion region and the first diffusion ring region, and the second barrier is one of the width w2 The ring is located in the first diffusion ring zone And the guard ring region; and the second pattern defined by the second mask comprises at least a light transmissive: a second diffusion region located at the center and having an outer diameter D2a; wherein the deep diffusion region Outer diameter The outer diameter D2 of the repeating diffusion zone is defined, the outer diameter of the first diffusion zone is defined by the outer diameter D1 of the first diffusion ring zone, and the outer diameter of the guard ring is the outer diameter DG of the guard ring zone. In addition, DG>D1>D2a>D2; wherein, when the alignment error value (that is, the center offset) of the two patterns formed by the two masks in the diffusion process is De, then w1 ≧De; and (D2+2w1)≧(D2a+De); wherein the diffusion process is a wet etching process followed by the following steps: (A) forming a first dielectric layer on the substrate (B) defining the first dielectric layer with the photoresist material by the first photomask; (C) removing the first dielectric layer portion of the light transmissive portion; (D) Forming a second dielectric layer on the substrate; (E) defining the second dielectric layer with the photoresist layer by the second photomask; (F) permeable portion The second dielectric layer is partially removed; (G) the substrate is wet etched such that the substrate regions not covered by the first and second dielectric layers are etched to form a recessed region; (H) the second on the substrate Dielectric layer removal; (I) Forming the second pattern on the substrate and the first dielectric layer by the second photomask and the photoresist material; (J) firstly placing the first barrier ring of the light permeable portion in a solution side etching manner Removing the dielectric layer, and then removing the photoresist material; (K) performing a shallow diffusion process on the substrate with a conductive material, and The material is not covered by the first dielectric layer and the region of the recessed region forms at least one electrically conductive diffusion layer. The method for processing a cumulative collapse photodiode according to claim 7, wherein the substrate is an n-type InP substrate or a substrate composed of GaAs, Si, or GaN material. The material of the first dielectric layer is tantalum nitride (Si ₃ N ₄ ); the conductive material is bismuth ion (Be) or zinc (Zn); the second dielectric value is cerium oxide (SiO ₂ ) . The method for manufacturing a cumulative collapse photodiode according to claim 7, wherein the method of forming the first dielectric layer and the second dielectric layer is a deposition process; and removing the first component of the permeable portion The electrical layer is one of the following: a wet etching process, and a dry etching process; and, the first and second shallow diffusion processes are thermal diffusion processes; wherein, 1 μm ≦ w1 ≦ 5 μm; 10 μm ≦ (D1- D2) ≦ 30 μm; and 1 μm ≦ (D2a-D2) ≦ 5 μm. A photomask device for use in a process of accumulating a collapsed photodiode, wherein a protective ring on the outer ring and a first in the middle are defined on a substrate for fabricating a cumulative collapse light diode a diffusion region and a deep diffusion region overlapping the center of the first diffusion region; the reticle device includes a first reticle and a second reticle respectively defining a first photoresist layer to the substrate a pattern and a second pattern, and performing a diffusion process according to the first pattern and the second pattern to form the deep diffusion region, the first diffusion region, and the guard ring; wherein the mask device is characterized by: The first pattern defined by the first reticle includes at least a light transmissive layer from the inner to the outer side: a centrally located outer diameter of one of the D2 repeating diffusions a first diffusion ring region having a diameter D1 and a guard ring region having an outer diameter DG; and the first pattern is opaque: the first barrier ring is located at a width w1 a second barrier ring between the repeating diffusion region and the first diffusion ring region and having a width w2 is located between the first diffusion ring region and the guard ring region; and, the second defined by the second mask The pattern includes at least a light transmissive portion: a second diffusion region located at the center and having an outer diameter D2a; wherein an outer diameter of the deep diffusion region is defined by an outer diameter D2 of the repeated diffusion region, the first The outer diameter of the diffusion zone is defined by the outer diameter D1 of the first diffusion ring zone, and the outer diameter of the guard ring is defined by the outer diameter DG of the guard ring zone; further, DG>D1>D2a>D2; When the alignment error value (ie, the center offset) of the two patterns formed by the two masks in the diffusion process is De, then w1≧De; and (D2+2w1)≧(D2a+De) . The photomask device according to claim 10, wherein 1 μm ≦ w1 ≦ 5 μm; 10 μm ≦ (D1 - D2) ≦ 30 μm; and 1 μm ≦ (D2a - D2) ≦ 5 μm.