TW449788B - P-type modified lateral silicon controlled rectifier structure for electrostatic discharge protection - Google Patents

Abstract

The present invention provides a silicon-controlled rectifier (SCR) used for electrostatic discharge protection. This SCR contains a P<SP>+</SP> type diffusion, instead of the N<SP>+</SP> type diffusion, which connects N-well with P-well. This P<SP>+</SP> bridging modified lateral SCR (PMSCR) structure has an action mechanism that is similar to the conventional modified lateral SCR (MLSCR). However, the triggering voltage of the present P<SP>+</SP> bridging modified lateral SCR is defined as the breakdown voltage from the P<SP>+</SP> bridging diffusion region to the N-well, and is reverse biased. Based on this invention, the triggering voltage of P<SP>+</SP> bridging modified lateral SCR is about 12 to 13 V, and this value is low enough to make the P<SP>+</SP> bridging modified lateral SCR be used individually as the electrostatic discharge protection apparatus. The human body model (HBM) test indicates that this P<SP>+</SP> bridging modified lateral SCR has very high efficiency of 6.7 V/mu m<SP>2</SP>. In addition, the P<SP>+</SP> bridging modified lateral SCR shows less sensitivity to the silicide degradation as compared with the modified lateral SCR and low voltage trigger SCR (LVTSCR).

Description

4 49 788 V. Description of the invention (1) 5_1 Field of invention: The present invention relates to a silicon controlled rectifier (SCR) for electrostatic discharge (ESD) protection. Discharge-protected ρ + bridging modified lateral silicon controlled rectifier (PMSCR) 〇5-2 Background of the invention: Silicon controlled rectifier is a known thyratron because it has a very high impedance state to extremely low The impedance state capability is widely used in power supply devices. For the same reason, a properly designed silicon controlled rectifier can be used as a very effective electrostatic discharge protection circuit ^ A cross-sectional view of a simple lateral silicon controlled rectifier (LSCR) is shown in the first figure

‘Basically a stone evening rectifier contains a pnpn structure. A stone-controlled rectifier structure 100 is a typical lateral silicon-controlled rectifier structure. This lateral silicon-controlled rectifier structure 100 is formed in a semiconductor layer 110. There is a lightly doped N-well 112 in the semiconductor layer Π0. There is another lightly doped P well 11 4 in the semiconductor layer 110, and it is adjacent to the N well 11 2. A heavily doped N-type (N +) region 1 2 0 is in 1 ^ well 112 and is in electrical contact with an anode 100—heavily doped? Type (? + 449788 V. Description of the Invention (2)) The region 126 is in the P well 114 and is in electrical contact with a cathode 20. A P + region 122 is in the N well 112 and is located between the N + region 120 and the P + region 126 and is in electrical contact with an anode 10. An N + region 1 24 is in the P well 114 and is located between the P + region 122 and the P + region 126 and is in electrical contact with a cathode 20. The field insulation region 132 is in the N well 112 and is located between the N + region 120 and the P + region 1 2 2. A field insulation region 1 3 6 is located in the P well 114, and is located between the N + region 124 and the P · {• region 126. The field insulation region 134 is in the N well 112 and the P well 114, and is located between the N well Π 2 and the P well 114, so as to partially overlap the junction surface 140 between the n well 112 and the P well 114. The P + region 122 in the N-well serves as the anode of the silicon controlled rectifier, in which holes flow to the N-well. The N + region j 24 in well P is used as the cathode of the silicon controlled rectifier, where electrons flow to well P. It is connected to well N by an N + contact 120 located in well N, and well p is connected by a well located in p The p + contact 126 is connected to it "" A silicon controlled rectifier can be regarded as two bipolar transistors. A PM transistor is formed with the anode as the emitter and the N well as the base and the P well as the collector. In addition, a cathode is formed with the emitter, the ρ well is used as the base, and the N well is used as the collector to form an η transistor. T2 . The equivalent circuit of this silicon controlled rectifier is shown in the second figure. In 苴, T1 and T2 respectively represent ρηρ224 and ηρη222 transistors', R?

And Rp-well 2 1 4 represents N-well resistance and P-well resistance. eU When a silicon controlled rectifier is used as an electrostatic discharge protection circuit, it is regarded as

Η

Page 788

Modification No. 89 ^ 15837 V. Description of the invention (3) One-connector device, anode plate N and remote relay one buckle ^ Open late connected at the beginning, and the cathode and P well connected at the beginning. To turn on the silicon-controlled rectifier, the cathode can be forward-biased by the hole current in p-well, just as n-Qiu is touched in the OS transistor, or 开启 nρ can be turned on by the electron current in N-well. At low currents, the typical ηρη gain is approximately one power greater than ρηρ, so starting an npri is easier than starting a pnp. Therefore, the trigger voltage (tHgger voltage) is defined as the cumulative breakdown voltage Uvaianche breakdown voltage from the well to the substrate, and the trigger current is also defined in a similar manner to the above. Silicon controlled rectifiers as electrostatic discharge protection can withstand relatively high electrostatic discharge stress (ESD stress). When the silicon controlled rectifier is triggered, it provides good protection. However, the problem with the prior art silicon controlled rectifiers is that their induced voltage is too high. In the more advanced CDD process, the cumulative breakdown voltage from η well to the substrate is about 50 V ^ so the initiation potential of the lateral silicon controlled rectifier is not low enough to allow it to be used alone for electrostatic discharge protection. In order to make Shi Xikong rectifier as an effective electrostatic discharge protection circuit, the induced potential must be lowered. A modified lateral silicon controlled rectifier (MLSCR) was proposed. It is done using an additional N + diffusion at the edge of the N well as shown in the third figure. — Silicon controlled rectifier structure 300 is a typical modified lateral silicon controlled rectifier structure. The modified lateral silicon controlled rectifier structure 300 is formed in a semiconductor layer 310. Within this semiconductor layer 3 10

Page 7 2001.05.18. 007 449788 V. Description of the invention (4) There is a lightly doped N well 3120. In this semiconductor layer 310, there is also a lightly doped P well 314, which is adjacent to the N well 31 2. An N + region 320 is in the N well 31 2 and is in electrical contact with an anode 10. A P + region 326 is in P well 314 and is in electrical contact with a cathode 20. A P + region 322 is in the N well 3 12 and is located between the N + region 32 0 and the P + region 32 6 and is in electrical contact with an anode 10. An N + region 324 is in the P well 314, is located between the P + region 322 and the P + region 326, and is in electrical contact with a cathode 20. An N + region 328 is between N well 312 and P well 3 14 and is located between P + region 322 and N + region 324, so that it partially overlaps the junction 3 between N well 3 1 2 and P well 31 4 3 4 0 . A field insulation region 33 2 is in the N well 312 and is located between the N + region 32 0 and the P + region 3 2 2. A field insulation region 3 3 4 is in the N well 3 1 2 and is located between the P + region 3 22 and the N + region 328. The field insulation region 336 is in the P well 3 14 and is located between the N + region 3 2 8 and the N + region 3 2 4. A field insulation region 3 3 8 is in P well 314 'and is located between N + region 324 and P + region 326. Now the collapse of Shi Xi controlled rectifier ^ I ..., / 仰 + outside the field η + expands to the collapse potential of the substrate, and the initiation potential is now about .20 -25V. However, compared to the breakdown potential of the gate oxide, the initiation potential of the modified lateral silicon 32 is still too large. If there is no effective secondary protection, Ϊ :: the controlled rectifier still cannot effectively protect the input connection. To further reduce the initiation potential, a gate diode can be used to place η

Page 8 V. Description of the invention (5) and edge to achieve, as shown in the fourth figure. A &gt; ε evening control rectifier structure 400 is a low voltage triggering sand control rectifier (a low voltage trigger SCR * LVTSCR) structure. The low-potential-triggered silicon-controlled rectifier structure 400 is formed in a semiconductor layer 410. There is a lightly doped N-well 412 in the semiconductor layer 410. There is another lightly doped P-well 414 in the semiconductor layer 410, which is adjacent to the N-well 41 2. An N + region 42 0 is in the N well 41 2 and is in electrical contact with an anode 10. A P + region 426 is in the P well 41 4 and is in electrical contact with a cathode 20. A P + region 42 2 is in the N well 4 12, is located between the N + region 42 0 and the P + region 426, and is electrically contacted to an anode 10. An N + region 424 is in P well 414 and is located between P + region 422 and P + region 426, and is in electrical contact with a cathode 20. An N + region 42 8 is between N well 412 and P well 41 4, and is located between P {area 4 2 2 and N + region 4 2 4, so that it partially overlaps between N well 41 2 and P well 41 4的 接面 4 4 0。 The joint surface 4 4 0. A field insulation region 4 3 2 is in the N well 41 2 ″ and is located between the N + region 4 2 0 and the P + region 4 2 2. A field insulation region 4 3 4 is in the N well 41 2 and is located between the p + region 422 and the N + region 428. The field insulation region 438 is in the P well 414 and is located between the N + region 424 and the P + region 426. A gate 450 and an insulator such as a hafnium oxide 4 5 2 are on the P well 41 4 and are located between the N + region 4 2 8 and the N + region 42 4 ′ and are in electrical contact with the cathode 20. Therefore, the gate 450, the N + region 428 and the N + region 424 form an nMOS-like structure and are essentially like an nMOS transistor. The initiation potential of the low-potential-triggered silicon-controlled rectifier is equivalent to the collapse potential of an nMOS transistor with the same insulator thickness and channel length as the aforementioned η M 0S structure.

Page 9 449783 ‘-V. Description of the invention (6) The initiation potential of this device is about 10-15V. Because of their low trigger potential, these devices are called low-potential-triggered silicon controlled rectifiers or LVTSCK for short. However, the electrostatic discharge efficiency of the silicon controlled rectifier caused by the low potential will decline due to the nMOS gate polarization, especially in the silicided metal process. To overcome these problems, the present invention proposes a new silicon controlled rectifier structure. 5-3 Object and Summary of the Invention The object of the present invention is to provide a new and improved silicon controlled rectifier. A P + region, rather than an N + region, is in wells N and P, so that this region partially overlaps the junction of wells N and P. The initiation potential of this new silicon-controlled rectifier is greater than the initiation potential of the low-voltage-triggered stone-controlled rectifier, but smaller than that of the modified lateral silicon-controlled rectifier. 〇 Another object of the present invention is to provide an effective electrostatic discharge protection device «to test the human body model performance of this new silicon controlled rectifier and to modify the horizontal silicon controlled rectifier and low potential induced silicon controlled rectifier. Compare results. This new silicon-controlled rectifier is found to be less efficient than modified lateral silicon-controlled rectifiers in both silicide-blocked structures and siHcided structures. Potential-triggered silicon-controlled rectifiers are better.

Page 10 4 49 788 V. Description of the invention (7) The purpose of the present invention is to use a p + connection to repair a lateral silicon controlled rectifier structure so that the Shixi controlled rectifier can be triggered at a low potential. The structure of the horizontal chopping rectifier is similar to the modified horizontal '= 2 device of the prior art. According to the present invention, in the connection modification horizontal dream control, Tian: Λ: includes at least a first lightly doped region formed on a semiconductor substrate as a well region, wherein the first lightly doped region has a first half Bismuth is, for example, p-type. In addition, a second lightly-doped region is formed on the two-body substrate t adjacent to the first lightly-doped domain 1 y to serve as one well and two ytterbium, which has a second conductivity type whose conductivity is opposite to the first Type II, Type II, and a first heavily doped region with a first conductivity type in the S-doped region, and are electrically closed to the -th node such as =-. _ And a second heavily doped region having a second conductivity type is formed at. In the lightly doped region, and electrically coupled to a second node, such as the anode, a third heavily doped region having a second conductivity type is formed in the second impurity region, and is located between the first heavily doped region and the first The double-doped region is electrically dimer and electrically coupled to the first node. And a fourth heavily doped region having a first-conducting I-type is formed in the second lightly doped region, and the two heavily doped regions and the third heavily doped region are electrically coupled to the Erlang point. And a fifth heavily doped P-type region is formed in the first, the second region and the second lightly doped region, so that the partial overlap = the junction between the hetero region and the second lightly doped region is: Between a heavily doped region and a fourth heavily doped region. : Article

^ 9788- V. Description of the invention (8):-The above-mentioned first lightly doped region is not absolutely necessary when the substrate is doped with the first conductive type time domain. 5-4 Detailed Description of the Invention: The preferred embodiments of the present invention will be discussed in detail later. The embodiment is used to describe a specific example of using the present invention and is not intended to limit the scope of the present invention. The invention proposes a new silicon controlled rectifier structure, in which a p + region

The non-N + region is in the N and p wells' so that the P + region partially overlaps the junction of the N and P wells. The new silicon controlled rectifier's current versus potential curve will also be measured to determine its initiating potential. And test the human body model (ΗBM) efficiency of this new silicon controlled rectifier and compare it with the results of modified lateral silicon controlled rectifier and low potential induced silicon controlled rectifier. The fifth figure is a preferred embodiment of the present invention. A schematic cross-sectional view. A silicon controlled rectifier structure 500 is a typical p + bridging modified lateral SCR ’PMSCR structure. The P + connection modifies the lateral silicon controlled rectifier structure 500 is formed in a semiconductor layer 510. There is a lightly doped N-well 512 in the semiconductor layer 510. A lightly doped P-well 514 is located in the semiconductor layer 5 10 and is adjacent to the N-well 5 12. One N + zone

Page 12 449788 V. Description of the invention (9) The domain 520 is in the N well 51 2 'and is in electrical contact with an anode 10. A p + region 526 is in P well 51 4 'and is in electrical contact with a cathode 20. A P + region 522 is in the N well 512 'and is located between the 1H region 520 and the P + region 526, and is in electrical contact with an anode 10. An N + region 524 is in P well 5 14 and is located between P + region 5 2 2 and P + region 5 2 6 'and is in electrical contact with a cathode 20. A p + region 528 is between N well 512 and p well 514 and is located between P + region 522 and N + region 524 'so as to partially overlap to the junction 540 between N well 5 1 2 and P well 5 1 4 » The field insulation region 532 is in the N well 512 and is located between the N + region 52 and the p + region 522. A field insulation region 5 34 is in the N well 512 and is located between the p + region 522 and the P + region 528. The field insulation region 5 36 is in the p-well 514 and is located between the P + region 528 and the N + region 5 24. The field insulation region 538 is in the p-well 514 and is located between the N + region 524 and the P + region 526.

The current vs. potential of the P + connection modifies the lateral silicon controlled rectifier as shown in Figure 6. Curves 61 to 63 are p + link modified lateral stone = flow device, repaired silicon controlled rectifier, flow device, and low potential induced silicon controlled rectification. "Flow to potential curve = system diagram. From the figure we can find p + connection repair J

The generator's bow I power level is about 12_13V1, which is greater than the low-potential lead = / claw device, but smaller than the modified lateral stone evening rectifier. The human body model efficiency of t is compared with the results of the controlled rectifier. Test P + connection to modify the lateral silicon controlled rectifier.

449788 V. Description of the Invention (ίο). All the structures to be tested are designed with the same size of 50 μm × 20 m, and the parameters of the installation design remain the same. The length of the nMOS gate in the low-potential induced silicon controlled rectifier is 0.5 μm. In addition, a structure with and without a si lie ide block mask must also be considered. For the human body model test, the initial potential was set to 100 volts and the increase was 50 volts. The test results are shown in Figure 7. It can be found that the p + link modified lateral silicon controlled rectifiers have high efficiency when blocking silicide_Mocked structure and siiicided structure, which are 6, 7KV and 5. 7KV, respectively. The performance indices are 6.7V / // ms and 5. 7V /. In addition, it can also be found that the p + link modified lateral silicon controlled rectifiers are found in structures that prevent silicided metals or structures that have silicided metals. The efficiency of its human body model is better than that of modified laterally-triggered silicon-controlled rectifiers. ^

The technology prior to the manufacture of the dream-controlled rectification of the present invention is not different and is well known and will be described in detail. The above description is only within the scope of the patent application for equivalent changes made in the spirit of the present invention to limit the scope of the present invention. There are no special restrictions on the methods and methods that can be used in the device structure. Therefore, it is not a preferred embodiment, and is not used. Anything that does not depart from or be modified by the present invention should be included in the following.

449788 Brief description of the diagram The first diagram shows a cross-sectional view of a typical lateral silicon controlled rectifier (LSCR). The second figure shows the equivalent circuit diagram of a lateral silicon controlled rectifier. The third figure shows a cross section of a typical modified lateral silicon controlled rectifier (MLSCR). The fourth figure shows a cross-section of a low-potential-triggered silicon controlled rectifier (LHSCR). The fifth figure shows a cross-sectional view of a P + link modified lateral silicon controlled rectifier (pMSCK) ° The sixth figure shows the P + linked modified lateral silicon controlled rectifier, a modified lateral stone controlled rectifier, and the low-current induced silicon controlled rectifier current. Curve diagram. The seventh figure shows the human body model (HBM) efficiency of the P + link modified lateral silicon controlled rectifier, modified horizontal stone controlled rectifier, and low-potential induced silicon controlled rectifier. 0 Representative symbols of main parts: 1 0 anode

ί 4 49 70 8 Schematic description of 20 cathode 1 0 0 typical lateral silicon controlled rectifier structure 112 lightly doped N well 114 lightly doped P well 120 heavily doped N-type region 122 heavily doped P-type region 124 heavily doped Miscellaneous N-type region 126 Heavily doped P-type region 132 Field insulating region 134 Field insulating region 1 3 6 Field insulating region 1 4 0 Joint surface .212 Rn_ffell, N well resistance 214 Rp_well, P well resistance 222 T2, npn transistor 224 T1, pnp transistor 3 0 0 Typical modified lateral silicon controlled rectifier structure 312 Lightly doped N-well 314 Lightly doped P-well 320 Heavy-doped N-type region 322 Heavy-doped P-type region 324 Heavy-doped N-type region 326 Heavily doped P-type region 328 Heavily doped N-type region

Page 16 449788 Brief description of the diagram 3 3 2 field insulation area 3 34 field insulation area 3 3 6 field insulation area 3 3 8 field insulation area 340 bonding surface 4 0 0 Typical low potential induced silicon controlled rectifier structure 4 1 2 light Doped N-well 4 1 4 Lightly doped P-well 420 Heavily-doped N-type region 422 Heavily-doped P-type region 424 Heavily-doped N-type region 426 Heavily-doped P-type region 428 Heavily-doped N-type region 4 3 2 Field insulation area 4 3 4 Field insulation area 4 3 8 Field insulation area 440 Bonding surface 4 5 0 Gate 4 5 2 Gate oxide 5 00 Typical P + connection modified lateral silicon controlled rectifier structure 51 2 Lightly doped N well 5 1 4 Lightly doped P well 520 Heavily doped N-type region. 5 2 2 Heavily doped P-type region

Page 17 4 49 788 Schematic illustration 5 24 heavily doped N-type region 526 heavily doped P-type region 5 2 8 heavily doped P-type region 5 3 2 field insulation region 5 3 4 field insulation region 5 3 6 field Insulation area 5 3 8 Field insulation area 5 4 0 Joining surface 61 P + connection Modified current vs. potential curve of lateral silicon controlled rectifier Figure 62 Modified current vs. potential curve of lateral silicon controlled rectifier Figure 6 3 Low potential induced silicon controlled rectifier Current vs. potential curve

Page 18

Claims (1)

^^ 78 8 Case No. 89115837 6. Scope of patent application A silicon controlled rectifier structure for electrostatic discharge protection includes: a semiconductor substrate; one having a first conductivity type and one having a second conductivity type, formed on the semiconductor bottom and having the first conductive well, and electrically coupled to— One has the second conductive well, and the electrical one has the well, and is located and electrically coupled to the light-to-to-second conductive, the first push, the first section, and the first conductive well, and is located and electrically coupled. To the fifth dopant, so as to be part, and located in the second dopant, the second dopant P-type, and the second-type heterotype region overlapping the third-doped first-type inner-type first-type inner type. Point; type 1 region of the miscellaneous region, the first well is formed in the semiconductor substrate; the two wells have conductivity opposite to that of the first well and are adjacent to the first well; the first doped region is formed at The first nodal point; a second doped region formed at the second node; a third doped region and the first region 'are formed between the first and second doped regions, and a fourth doped region and the Cap as well as 2. a well with the range of the first patent application a first insulating region, heteroaryl-shaped region and the third doped region may be at least one oxide. A region 'is formed between the second and third doped regions, and between the first well and the second well of the second well between the junction region and the fourth doped region. The silicon-controlled rectifier structure described in the item further includes being formed in the first well and located between the first doped regions, wherein the first field is insulated, and the region to Page 19: 2001.05.18.019 4 4 9 7 8 8 ---- ^^ 891158 ^ 7 __Amendment _____ VI. Scope of patent application 3. Silicon controlled rectifier structure as described in item 1 of the scope of patent application And further includes a first% insulation region formed in the first well and located between the third doped region and the fifth doped region, wherein the second field insulation region may be at least an oxide. 4. The silicon controlled rectifier structure described in item 1 of the scope of patent application, further comprising one or two field insulation regions formed in the second well and located between the fourth doped region and the fifth doped region. 'Wherein the third field insulation region may be an oxide. 5. The silicon-controlled rectifier structure described in item 1 of the scope of the patent application, further comprising four field insulation regions formed in the second well and located between the second doped region and the fourth doped region, The fourth field insulation region may be at least one halide. 6. The silicon controlled rectifier structure described in item 1 of the patent scope, wherein the first conductivity type is p-type and the second conductivity type is N-type. 7. A silicon controlled rectifier structure for electrostatic discharge protection, the structure comprising at least: a semiconductor substrate; a doped p-type well formed in the semiconductor substrate; a doped N-type well formed on the semiconductor substrate Within the material, and with the doping p Page 20, 2001. 05.18. 〇2〇 ^ 788 __ Case No. 89115837 ___ month said ____ Six, the scope of the patent application &quot; 'adjacent to the well; a first doped N-type region, formed in the doping An N-type well is electrically coupled to an anode; ^ a first doped P-type region is formed in the doped p-type well and is electrically coupled to a cathode; μ a second doped P-type region is formed at The doped N-type well is located between the first doped N-type region and the first doped p-type region, and is electrically light-coupled to the anode; a second doped N-type region is formed in the doped In a hetero-p-type well, located between the second doped p-type region and the first doped p-type region, and = coupled to the cathode; 'a third doped p-type region is formed in the doped The N-type well and the doped p-type well are partially overlapped to the junction between the doped N-type well and the doped p-type well, and are located in the second doped N-type region and the second doped ρ between regions. / 8 · The silicon controlled rectifier structure described in item 7 of the scope of patent application, further comprising a first field insulation region formed in the doped well and located in the first doped N-plastic region and the second doped region. Between hetero-p-type regions, the first field insulation region may be at least an oxide. 9. The silicon controlled rectifier structure described in item 7 of the scope of the patent application, further comprising a second field insulation region formed in the doped profiled well and located in the second doped P-plastic region and the third doped region. Hetero-p-type region, wherein the second Page 21 2001.05.18-〇21 449788 ___Case No. 89115837 __ [Yuexiu 4_16. The scope of the patent application field insulation area can be at least one oxygen material ° 1 0. As described in item 7 of the scope of patent application The silicon-controlled rectifier structure further includes a third field insulation region formed in the doped P-type well and located between the third doped P-type region and the second doped N-type region, wherein the third field The insulating region may be at least an oxygen compound. 11. The silicon controlled rectifier structure described in item 7 of the scope of patent application, further comprising a fourth field insulation region formed in the doped P-type well and located in the second doped N-type region and the first doped region. Among the hetero-P-type regions, the fourth field insulation region may be at least one oxide. 12. A silicon controlled rectifier structure for electrostatic discharge protection, the structure comprising at least: a doped substrate having a first conductivity type; a well having a second conductivity type is formed in the substrate, and its conductivity is opposite In the first conductivity type; a first doped region having the second conductive disc formed in the well and electrically coupled to a first node; a second doped region having the first conductive disc formed in In the substrate, and electrically coupled to a second node; a third doped region having the first conductive substrate formed in the well; and located between the first doped region and the second doped region And is electrically coupled to the first node; 3 788, Patent Application No. 1 8.9115 Lang 7 Wai Seisetsu Amendment Wherein a fourth doped region having the second conductivity type is formed on the substrate and is located between the third doped region and the second doped region, and is electrically closed to the second node; and -The fifth and fifth p-type regions are formed in the substrate and the well, so that two portions overlap the junction surface between the substrate and the well, and are located in the second doped region and the fourth doped region. Miscellaneous districts. 1 3 _ The silicon controlled rectifier structure described in item 12 of the scope of patent application, further comprising a first field insulation region formed in the well and located between the first doped region and the third doped region , Wherein the first field insulation region may be at least one oxide. 1 4. The silicon controlled rectifier structure according to item 12 of the scope of the patent application, further comprising a second field insulation region formed in the well and located between the third doped region and the fifth doped region. The second field insulation region may be at least one oxide. 1 5. The silicon-controlled rectifier structure according to item 12 of the scope of the patent application, further comprising a third field insulation region formed in the substrate and located between the fifth doped region and the fourth doped region. Between, wherein the third field insulation region may be at least one oxide. 16. The silicon-controlled rectifier structure described in item 12 of the scope of the patent application / application, further comprising a fourth field insulation region 'formed in the substrate and located in the fourth dopant. Page 23 2001.05.18.23 4 4 9 7 8 B _Case No. 89115837 _ Amended Month_ Six. Between the patent application scope and the second doped region, where the fourth field insulation region can be at least one Oxide. 17. The silicon controlled rectifier structure according to item 12 of the scope of the patent application, wherein the first conductive type is a P type and the second conductive type is an N type. Page 24 2001.05.18. 024