CN101179097A - SOI high-pressure component - Google Patents

Abstract

SOI high-voltage device pertains to SOI high-voltage semiconductor device in electron technology field. The SOI high-voltage device provided by the invention comprises a diode, LDMOS and LIGBT. The main technical scheme is to change the cathode, drain electrode and collecting electrodes of conventional solid shape into annular ones and make the longitudinal electric field distribution of SOI high-voltage device more uniform when the device is in the cutoff state, so as to improve breakdown voltage.of SOI high-voltage device. The invention discards the normally used way of improving layer I withstand voltage to improve the vertical withstand voltage of SOI high-voltage device and achieves the effect of increasing vertical withstand voltage of SOI high-voltage device likewise by the way of changing local structure of device to improve withstand voltage of top silicon layer. The invention is all compatible with conventional CD process and will not increase the difficulty and cost of preparation process and has strong feasibility of implementation.

Description

The SOI high tension apparatus

Technical field

The invention belongs to electronic technology field, relate to semiconductor high-voltage device, relate in particular to the lift technique of the puncture voltage of SOI high tension apparatus and SOI high tension apparatus.

Background technology

The SOI integrated circuit has characteristics such as high speed, low-power consumption, high integration, minimum ghost effect and good isolation, and has weakened latch up effect and possessed strong anti-irradiation ability, and therefore, the SOI integrated circuit has obtained fast development in recent years.

The SOI high tension apparatus is as the key components of SOI high voltage integrated circuit, and its puncture voltage has material impact to the performance of entire circuit.In the SOI high voltage integrated circuit commonly used, the SOI high tension apparatus mainly comprises SOI high-voltage diode, SOI high-voltage LDMOS device and SOI high pressure LIGBT device, and its structure is respectively shown in Fig. 1～4.For conventional SOI high-voltage diode (as shown in Figure 2), its structure comprises substrate 5, I layer 7, drift region 2, anode 1, negative electrode 3, anode metal lead-in wire 6 and cathodic metal lead-in wire 4; When the SOI high-voltage diode is under the off state, there is high pressure between its negative electrode and the anode.For conventional SOI high-voltage LDMOS device (as shown in Figure 3), its structure comprises substrate 5, I layer 7, drift region 2, channel region 8, drain electrode 10, grid 11, source electrode 12, source metal lead-in wire 6 and drain metal lead-in wire 4; When the SOI high-voltage LDMOS device is under the off state, there is high pressure between its drain electrode and the source/drain.For conventional SOI high pressure LIGBT device (as shown in Figure 4), its structure comprises substrate 5, I layer 7, drift region 2, channel region 8, collector electrode 13, grid 11, emitter 14, collector electrode metal lead-in wire 4 and emitter metal lead-in wire 6; When SOI high pressure LIGBT device is under the off state, there is high pressure between its collector electrode and the grid/emitter.

When high-voltage diode is under the off state, there is high pressure between negative electrode and the anode, the voltage that puts on when it is breakdown between negative electrode and the anode is called lateral breakdown voltage; Also have high pressure between negative electrode and the substrate simultaneously, the voltage that puts on when it is breakdown between negative electrode and the substrate is called vertical puncture voltage; The actual breakdown voltage of high-voltage diode depends on the smaller value in lateral breakdown voltage and the vertical puncture voltage.Lateral breakdown voltage can be improved by increasing means such as drift region length.And vertically puncture voltage because depletion layer can be expanded to substrate from the interface of drift region and substrate, so most of voltage can be born by substrate, so vertically puncture voltage depends primarily on substrate concentration, is easy to control in the manufacturing in the body silicon diode; And in the SOI high-voltage diode, owing to accumulate or inversion layer near forming on the interface of oxygen buried layer at substrate, depletion layer can not expanded to substrate, so the longitudinal voliage of SOI high-voltage diode is only born by top silicon layer and silicon dioxide buried regions, vertically puncture voltage is generally low than body silicon high-voltage diode, and can not get a promotion by the means that change substrate concentration.Therefore vertical puncture voltage of SOI high-voltage diode usually becomes the key factor that limits its puncture voltage.

Putting on the negative electrode of SOI high-voltage diode and the longitudinal voliage between the substrate is made of two parts: put on the voltage on the silicon layer of top and put on voltage in the silicon dioxide buried regions.The vertical puncture voltage of SOI high-voltage diode by top silicon layer puncture voltage and oxygen buried layer puncture voltage and the decision.As shown in figure 14, under regular situation, put on electric-field intensity distribution that the voltage on the silicon layer of top forms generally top silicon layer and silicon dioxide buried regions reach maximum at the interface, so the voltage of top silicon layer puncture voltage when to be this interface breakdown.

Under the off state of SOI high-voltage LDMOS device, the withstand voltage situation between drain electrode and grid, the source electrode is similar to the withstand voltage situation between the negative electrode and anode under the diode off state; Under the off state of SOI high pressure LIGBT device, collector electrode and grid, the withstand voltage situation between the emitter is similar to the withstand voltage situation between the negative electrode and anode under the diode off state.Therefore, be used to promote the puncture voltage that all can similarly be used to promote SOI high-voltage LDMOS device and SOI high pressure LIGBT device on the engineering philosophy of SOI high-voltage diode puncture voltage.

Below introduce the method for three kinds of common vertical puncture voltages of raising SOI high tension apparatus:

First kind as shown in Figure 5, resistance field plate (SIPOS) is introduced at interface at top silicon layer and silicon dioxide buried regions, electric current in the resistance field plate will force along the electric field of field plate direction and evenly distribute, and the electric field in the silicon dioxide buried regions is improved and electric field in the silicon layer of top is constant substantially.Use this method vertical puncture voltage of SOI high tension apparatus can be significantly improved.The shortcoming of this method is that SIPOS is higher to technological requirement, and reverse leakage current is wayward.

Second kind as shown in Figure 6, introduce the homotype impurity of doses in top silicon layer bottom, the critical breakdown electric field at the interface of top silicon layer and silicon dioxide buried regions is risen, according to the Gauss theorem under the no interface charge condition, electric field in the buried regions is proportional with electric field at the interface, interface critical breakdown electric field rising makes the corresponding rising of electric field in the buried regions, and device electric breakdown strength increases.The shortcoming of this method is that the impurity of bottom needs to form, and can not use this device of SOI made of standard before wafer bonding.

The third introduces fixed charge at the interface at top silicon layer and silicon dioxide buried regions as shown in Figure 7, and electric field boundary condition is at the interface changed, and the electric field in the silicon dioxide buried regions increases under charge effect, and puncture voltage is improved.The shortcoming of this method is also not have at present the introducing method of good interface charge.

More than three kinds of methods all be that withstand voltage to be that approach improves the SOI high tension apparatus vertically withstand voltage to improve the I layer, but all must on conventional CD technology basis, need to increase processing step, technology difficulty and cost all significantly increase than common standard CD technology, do not find to use the commercial product of above method at present as yet.

Summary of the invention

SOI high tension apparatus provided by the invention, what abandoned common employing is that approach improves vertically withstand voltage mode of SOI high tension apparatus to improve the I layer withstand voltage, is that approach reaches vertically withstand voltage effect of raising SOI high tension apparatus equally by changing the device partial structurtes to improve the top silicon layer withstand voltage, the present invention can be compatible entirely with conventional CD technology, comparing with the preparation technology of conventional SOI high tension apparatus does not increase technology difficulty and cost, possesses very strong exploitativeness.

The present invention is achieved through the following technical solutions:

A kind of SOI high-voltage diode shown in Fig. 8,9, comprises substrate 5, I layer 7, drift region 2, anode 1, negative electrode 3, anode metal lead-in wire 6 and cathodic metal lead-in wire 4.It is characterized in that negative electrode 3 is annular heavy doping negative electrode.

A kind of SOI high-voltage LDMOS device shown in Fig. 8,16, comprises substrate 5, I layer 7, drift region 2, channel region 8, drain electrode 10, grid 11, source electrode 12, source metal lead-in wire 6 and drain metal lead-in wire 4.It is characterized in that drain electrode 10 is annular heavy doping drain electrode.

A kind of SOI high pressure LIGBT device shown in Fig. 8,17, comprises substrate 5, I layer 7, drift region 2, channel region 8, collector electrode 13, grid 11, emitter 14, collector electrode metal lead-in wire 4 and emitter metal lead-in wire 6.It is characterized in that collector electrode 13 is annular heavy doping collector electrode.

In the technique scheme, for three kinds of devices, described annular heavy doping negative electrode (drain electrode or collector electrode) can be positive annular heavy doping negative electrode (drain electrode or a collector electrode), also can be oval ring (as shown in figure 13) heavy doping negative electrode (drain electrode or collector electrode); The external diameter R of described annular heavy doping negative electrode (drain electrode or collector electrode) ₁With internal diameter R ₂Preferably satisfy relation: $\frac{{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="S2007100506579E00011.png,S2007100506579E00021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}^2}{{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="S2007100506579E00021.png,S2007100506579E00041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1}^2}=\frac{\mathrm{qN}(t_{\mathrm{Si}}-x_j)}{{\mathrm{\&epsiv;}}_{\mathrm{Si}}{E}_m},$ Wherein q is an elementary charge, and N is the drift region doping content, t _SiBe drift region thickness, x _jBe the junction depth of negative electrode (drain electrode or collector electrode), ε _SiBe the dielectric constant of silicon, E _mIt is the critical breakdown electric field of silicon; The ring medial region of described annular heavy doping negative electrode (drain electrode or collector electrode) can be insulating regions (as shown in figure 11), also can be and the identical zone (as shown in Figure 9) of 2 doping, drift region can also be and the opposite heterogeneous doped region 9 (as shown in figure 10) of drift region 2 doping; The ring medial region of described annular heavy doping negative electrode (drain electrode or collector electrode) if with the drift region 2 opposite heterogeneous doped region 9 that mixes, described heterogeneous doped region 9 may extend to 2 inside, drift region in a longitudinal direction, may extend to the external diameter R that is no more than annular heavy doping negative electrode (drain electrode or collector electrode) in a lateral direction ₁Scope.

SOI high-voltage LDMOS device, the withstand voltage situation of SOI high pressure LIGBT device under off state are similar to the withstand voltage of SOI high-voltage diode, therefore, be applicable on the engineering philosophy of making SOI high-voltage diode negative electrode all applicable to the drain electrode of making the SOI high-voltage LDMOS device and the collector electrode of SOI high pressure LIGBT device; Can promote on the engineering philosophy of SOI high-voltage diode puncture voltage also all applicable to the puncture voltage that promotes SOI high-voltage LDMOS device and SOI high pressure LIGBT device.Because SOI high-voltage diode, SOI high-voltage LDMOS device and the similitude of SOI high pressure LIGBT device on breakdown characteristics, the puncture voltage that hereinafter will omit SOI high-voltage LDMOS device and SOI high pressure LIGBT device promotes principle, and the puncture voltage of only setting forth two kinds of specific implementations (the SOI high-voltage diode that the heavily doped SOI high-voltage diode of hollow cathode, hollow cathode heavy doping combine with the inboard heterogeneous doping of ring) of SOI high-voltage diode promotes principle.

In the SOI high-voltage diode, in the top silicon layer (being the drift region) puncture of silicon responsive to electric field level, and the silicon maximum field intensity of bearing generally can be thought steady state value E along the longitudinal direction _mSo the puncture voltage of top silicon layer is exactly that optional position, vertical aspect reaches and can bear maximum field intensity E _mThe time voltage.Simultaneously, the voltage in the silicon layer of top is electric field path integral longitudinally wherein, so even more if top silicon layer electric field strength longitudinally distributes, then the maximum breakdown voltage of top silicon layer is big more.In the conventional SOI high-voltage diode (as shown in Figure 2), the longitudinal electric field gradient is provided by (1) formula:

$\frac{{\&PartialD;E}_z}{\&PartialD;z}=\frac{\mathrm{qN}}{{\mathrm{\&epsiv;}}_{\mathrm{Si}}},0<z<t_{\mathrm{Si}}---\left(1\right)$

As Fig. 9, E _zAlong the negative direction of z axle, from N ⁺N ^-It is high more to tie electric field far away more, at the z=0 E of top silicon layer and I bed boundary place just _zMaximum is arranged, equal the critical breakdown electric field E of silicon when this value _mThe time SOI high-voltage diode puncture, this moment N ⁺N ^-The electric field at knot place does not reach E as yet _mIf can offset the influence of (1) formula and (2) formula is set up by introducing certain mechanism, then the puncture voltage of SOI high-voltage diode be improved:

$E_z{|}_{z=0}=E_z{|}_{z=t_{\mathrm{Si}}-x_j}=E_m---\left(2\right)$

Essence of the present invention is to change the cathode shape of SOI high-voltage diode into annular by the circle of routine, thereby strengthens N ⁺N ^-The curvature effect of knot position improves N ⁺N ^-Near the knot electric field, and place, I bed boundary and N ⁺N ^-The knot distance is far away, unaffected substantially, finally realizes N ⁺N ^-Near the knot electric field equates with the electric field of position, I bed boundary and (2) formula is set up, thereby the puncture voltage of SOI high-voltage diode is improved.In order to strengthen ⁺N ^-The curvature effect of knot position, following two the concrete approach of optional usefulness: hollow cathode heavy doping, hollow cathode heavy doping combine with the heterogeneous doping in the center of circle.

Hollow cathode heavy doping increases N by reducing negative electrode heavily doped region Method for Area ⁺N ^-The curvature of knot position.The circular cathode heavily doped region of conventional relatively SOI high-voltage diode, the heavily doped SOI high-voltage diode of hollow cathode have the littler negative electrode heavily doped region (as shown in Figure 9) of area, according to Gauss theorem, can be similar to and think N ⁺N ^-Junction area changes the new electric field E ' in back _zWith original electric field E _zSatisfy following relation:

$(2\mathrm{\&pi;}{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="S2007100506579E00021.png,S2007100506579E00041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1}^2-2\mathrm{\&pi;}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="S2007100506579E00011.png,S2007100506579E00021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}^2)\&CenterDot;{E^{\&prime;}}_z{|}_{z=t_{\mathrm{Si}}-x_j}=2\mathrm{\&pi;}{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="S2007100506579E00021.png,S2007100506579E00041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1}^2\&CenterDot;E_z{|}_{z=t_{\mathrm{Si}}-x_j}---\left(3\right)$

R wherein ₂, R ₁The inside and outside radius of corresponding ring-type cathode structure.By (3) formula as can be seen the heavily doped SOI high-voltage diode of hollow cathode at N ⁺N ^-Have the electric field higher than original conventional structure near the knot, this shows N ⁺N ^-The curvature effect of knot can improve Electric Field Distribution to a certain extent to be made it than conventional structure more near ideal situation.If by suitable device parameters R ₂, R ₁Choose and make the establishment of (2) formula, then vertical withstand voltage being improved of device.In conjunction with the boundary condition of (1) formula correspondence,, obtain the inside and outside radius R of hollow cathode with (3) formula substitution (2) formula ₂, R ₁The relation that should satisfy:

$\frac{{R_2}^2}{{R_1}^2}=\frac{\mathrm{qN}(t_{\mathrm{Si}}-x_j)}{{\mathrm{\&epsiv;}}_{\mathrm{Si}}{E}_m}---\left(4\right)$

In the formula, q is an elementary charge, and N is the drift region doping content, t _SiBe top silicon layer thickness (being drift region thickness), x _jBe the junction depth of negative electrode, ε _SiBe the dielectric constant of silicon, E _mIt is the critical breakdown electric field of silicon.Following formula can be used as the reference that the heavily doped SOI high-voltage diode of hollow cathode parameter is provided with, and in practical engineering application, should be foundation with (4) formula, draws optimized results in conjunction with numerical simulation.

For the SOI high-voltage diode that hollow cathode heavy doping combines with the inboard heterogeneous doping of ring, N ⁺N ^-The increase of knot position curvature will be by reducing the realization that combines with the heterogeneous doping of introducing of negative electrode heavily doped region area.The effect of heterogeneous doping is at N ⁺N ^-Form impurity compensation near the knot, make N ⁺N ^-Near the knot equivalent impurity concentration reduces.Can see by (2) formula, if replace actual doping content N, then the inside radius R of hollow cathode with lower equivalent impurity concentration N ' ₂Can reduce, the dead resistance of negative contact zone uses hollow cathode heavy doping lower than simple.

With common SOI material is example, and general general thicker SOI material parameter is that 20 μ m top silicon, 3 μ m bury oxygen.The conventional SOI high-voltage diode puncture voltage of making on this material is difficult to reach 600V, and the above puncture voltage of 600V is the commonplace requirement of industrial circle.The high-voltage diode that the present invention can make 20 μ m top silicon, 3 μ m bury on the oxygen material reaches the above puncture voltage of 600V.Before this, such effect normally needs the higher technology of more complicated cost to realize.Figure 15 has provided the present invention and specifically has been applied to top silicon to be mixed with concentration be 5.2*10 ¹⁴/ cm ³The SOI material of N type impurity on the result.Utilizing numerical simulation software MEDICI to carry out quantitative analysis shows: the SOI high tension apparatus (as shown in Figure 1) that is the R of conventional structure ₂The withstand voltage of the SOI high tension apparatus of=0 correspondence is 578V, and puncture voltage of the present invention has increased by 6.74% than conventional structure SOI high tension apparatus under the optimization situation, and this shows that the relative conventional structure of the present invention possesses the advantage on the performance.Contrast the present invention and conventional structure can find that they can use identical technological process manufacturing, and the difference of the two only is embodied in the difference of domain local figure.In the flow process, the local figure of domain is general irrelevant with cost, so uses the manufacturing cost of device of the present invention and conventional device identical and performance is better than conventional device, and the present invention has certain Practical significance.

Description of drawings

Fig. 1 is the floor map of conventional SOI high tension apparatus, and negative electrode (drain electrode or collector electrode) is a solid circles.Wherein, 1 expression anode, 2 expression drift regions, 3 expression negative electrodes, 10 expression drain electrodes, 12 expression source electrodes, 13 expression collector electrodes, 14 expression emitters.

Fig. 2 is the generalized section of conventional SOI high-voltage diode along radial direction.Wherein, 5 expression substrates, 7 expression I layers, 6 expression anode metal lead-in wires, 4 expression cathodic metal lead-in wires

Fig. 3 is the generalized section of conventional SOI high-voltage LDMOS device along radial direction.Wherein, 8 expression channel regions, 10 expression drain electrodes, 11 expression grids, 12 expression source electrodes, 6 expression source metal lead-in wires, 4 expression drain metal lead-in wires.

Fig. 4 is the generalized section of conventional SOI high pressure LIGBT device along radial direction.Wherein, 13 expression collector electrodes, 11 expression grids, 14 expression emitters, 4 expression collector electrode metal lead-in wires, 6 expression emitter metal lead-in wires.

Fig. 5 is the generalized section of a kind of existing SOI high tension apparatus along radial direction, wherein, and 15 expression resistance field plates.

Fig. 6 is the generalized section of a kind of existing SOI high tension apparatus along radial direction, wherein, and bottom, 16 expression drift region homotype impurity.

Fig. 7 is the generalized section of a kind of existing SOI high tension apparatus along radial direction, wherein, and the fixed charge of 17 expression drift regions and I bed boundary.

Fig. 8 is the floor map of SOI high tension apparatus of the present invention, and negative electrode/drain/collector is shaped as positive annular.

Fig. 9 is the generalized section of SOI high-voltage diode of the present invention along radial direction.

Figure 10, Figure 11, Figure 12 are the embodiment schematic diagrames that SOI high tension apparatus hollow cathode drain/collector of the present invention heavy doping combines with the inboard heterogeneous doping of ring.Wherein, the inboard heterogeneous doped region of 9 representative rings.

Figure 13 is the floor map of SOI high tension apparatus of the present invention, and negative electrode/drain/collector is shaped as oval ring.

Figure 14 is the contrast of the longitudinal electric field distribution map of conventional SOI high tension apparatus, SOI high tension apparatus longitudinal electric field distribution map of the present invention, desirable SOI high tension apparatus longitudinal electric field distribution map.

Figure 15 is the puncture voltage situation of change of SOI high-voltage diode of the present invention correspondence under different inside radius R2, outer radius R1 situation.

Figure 16 is the generalized section of SOI high-voltage LDMOS of the present invention along radial direction.

Figure 17 is the generalized section of SOI high pressure LIGBT of the present invention along radial direction.

Embodiment

One, the SOI high tension apparatus of positive annular heavy doping negative electrode (drain electrode or collector electrode).The SOI high-voltage diode that comprises positive annular heavy doping negative electrode, the SOI high-voltage LDMOS device of positive annular heavy doping drain electrode, the SOI high pressure LIGBT device of positive annular heavy doping collector electrode.

In the such scheme, the external diameter R of described annular heavy doping negative electrode (drain electrode or collector electrode) ₁With internal diameter R ₂Preferably satisfy relation: $\frac{{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="S2007100506579E00011.png,S2007100506579E00021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}^2}{{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="S2007100506579E00021.png,S2007100506579E00041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1}^2}=\frac{\mathrm{qN}(t_{\mathrm{Si}}-x_j)}{{\mathrm{\&epsiv;}}_{\mathrm{Si}}{E}_m},$ Wherein q is an elementary charge, and N is the drift region doping content, t _SiBe drift region thickness, x _jBe the junction depth of negative electrode (drain electrode or collector electrode), ε _SiBe the dielectric constant of silicon, E _mIt is the critical breakdown electric field of silicon.

In the such scheme, the ring medial region of described annular heavy doping negative electrode (drain electrode or collector electrode) can be an insulating regions, also can be and the identical zone of 2 doping, drift region.

Two, the SOI high tension apparatus of oval ring heavy doping negative electrode (drain electrode or collector electrode).The SOI high-voltage diode that comprises oval ring heavy doping negative electrode, the SOI high-voltage LDMOS device of oval ring heavy doping drain electrode, the SOI high pressure LIGBT device of oval ring heavy doping collector electrode.

In the such scheme, the external diameter R of described annular heavy doping negative electrode (drain electrode or collector electrode) ₁With internal diameter R ₂Preferably satisfy relation: $\frac{{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="S2007100506579E00011.png,S2007100506579E00021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}^2}{{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="S2007100506579E00021.png,S2007100506579E00041.png"\; state="\{\{state\}\}">R</figure-callout>}}_1}^2}=\frac{\mathrm{qN}(t_{\mathrm{Si}}-x_j)}{{\mathrm{\&epsiv;}}_{\mathrm{Si}}{E}_m},$ Wherein q is an elementary charge, and N is the drift region doping content, t _SiBe drift region thickness, x _jBe the junction depth of negative electrode (drain electrode or collector electrode), ε _SiBe the dielectric constant of silicon, E _mIt is the critical breakdown electric field of silicon.

In the such scheme, the ring medial region of described annular heavy doping negative electrode (drain electrode or collector electrode) can be an insulating regions, also can be and the identical zone of 2 doping, drift region.

Three, positive annular heavy doping negative electrode (drain electrode or collector electrode) with encircle the SOI high tension apparatus that the heterogeneous doping of medial region combines.Comprise the SOI high-voltage diode that positive annular heavy doping negative electrode combines with the heterogeneous doping of ring medial region, the SOI high-voltage LDMOS device that positive annular heavy doping drain electrode combines with the heterogeneous doping of ring medial region, the SOI high pressure LIGBT device that positive annular heavy doping collector electrode combines with the heterogeneous doping of ring medial region.

In the such scheme, the inboard heterogeneous doped region of described ring (9) vertically may extend to inside, drift region (2), laterally may extend to the external diameter R that is no more than annular heavy doping negative electrode ₁Scope.

Description according to above three kinds of concrete real-time modes, in fact the present invention can realize a variety of SOI high tension apparatus with different structure, the division ring medial region needs outside the device of heterogeneous doping, other devices all do not need the additional process flow process in preparation process, only need to change graphics processing, this circularizes shape and gets final product by the solid shape of routine such as: the mask that negative electrode (drain electrode or collector electrode) heavy doping is injected.

Claims (21)

1. a SOI high-voltage diode comprises substrate (5), I layer (7), drift region (2), anode (1), negative electrode (3), anode metal lead-in wire (6) and cathodic metal lead-in wire (4); It is characterized in that negative electrode (3) is annular heavy doping negative electrode.

2. SOI high-voltage diode according to claim 1 is characterized in that, described annular heavy doping negative electrode is positive annular heavy doping negative electrode or oval ring heavy doping negative electrode.

3. SOI high-voltage diode according to claim 1 and 2 is characterized in that, the external diameter R of described annular heavy doping negative electrode ₁With internal diameter R ₂Satisfy relation: $\frac{{R_2}^2}{{R_1}^2}=\frac{\mathrm{qN}(t_{\mathrm{Si}}-x_j)}{{\mathrm{\&epsiv;}}_{\mathrm{Si}}{E}_m},$ Wherein q is an elementary charge, and N is the drift region doping content, t _SiBe drift region thickness, x _jBe the junction depth of negative electrode, ε _SiBe the dielectric constant of silicon, E _mIt is the critical breakdown electric field of silicon.

4. according to claim 1,2 described SOI high-voltage diodes, it is characterized in that the ring medial region of described annular heavy doping negative electrode is and the opposite heterogeneous doped region (9) of drift region (2) doping.

5. according to claim 1,2 or 3 described SOI high-voltage diodes, it is characterized in that the ring medial region of described annular heavy doping negative electrode is and the identical zone of drift region (2) doping.

6. according to claim 1,2 or 3 described SOI high-voltage diodes, it is characterized in that the ring medial region of described annular heavy doping negative electrode is an insulating regions.

7. SOI high-voltage diode according to claim 4 is characterized in that, described heterogeneous doped region (9) extends longitudinally to inside, drift region (2), extends laterally to the external diameter R that is no more than annular heavy doping negative electrode ₁Scope.

8. a SOI high-voltage LDMOS device comprises substrate (5), I layer (7), drift region (2), channel region (8), drain electrode (10), grid (11), source electrode (12), source metal lead-in wire (6) and drain metal lead-in wire (4); It is characterized in that drain electrode (10) is annular heavy doping drain electrode.

9. SOI high-voltage LDMOS device according to claim 8 is characterized in that, described annular heavy doping drain electrode is positive annular heavy doping drain electrode or oval ring heavy doping drain electrode.

10. according to Claim 8 or 9 described SOI high-voltage LDMOS devices, it is characterized in that the external diameter R of described annular heavy doping drain electrode ₁With internal diameter R ₂Satisfy relation: $\frac{{R_2}^2}{{R_1}^2}=\frac{\mathrm{qN}(t_{\mathrm{Si}}-x_j)}{{\mathrm{\&epsiv;}}_{\mathrm{Si}}{E}_m},$ Wherein q is an elementary charge, and N is the drift region doping content, t _SiBe drift region thickness, x _jBe the junction depth of drain electrode, ε _SiBe the dielectric constant of silicon, E _mIt is the critical breakdown electric field of silicon.

11. according to Claim 8 or 9 described SOI high-voltage LDMOS devices, it is characterized in that the ring medial region of described annular heavy doping drain electrode be and the opposite heterogeneous doped region (9) of drift region (2) doping.

12. according to Claim 8,9 or 10 described SOI high-voltage LDMOS devices, it is characterized in that the ring medial region of described annular heavy doping drain electrode be and the identical zone of drift region (2) doping.

13. according to Claim 8,9 or 10 described SOI high-voltage LDMOS devices, it is characterized in that the ring medial region of described annular heavy doping drain electrode is an insulating regions.

14. SOI high-voltage LDMOS device according to claim 11 is characterized in that, described heterogeneous doped region (9) extends longitudinally to inside, drift region (2), extends laterally to the external diameter R that is no more than annular heavy doping drain electrode ₁Scope.

15. a SOI high pressure LIGBT device comprises substrate (5), I layer (7), drift region (2), channel region (8), collector electrode (13), grid (11), emitter (14), collector electrode metal lead-in wire (4) and emitter metal lead-in wire (6); It is characterized in that described collector electrode (13) is an annular collector electrode.

16. SOI high pressure LIGBT device according to claim 15 is characterized in that, very positive annular heavy doping collector electrode of described annular heavy doping current collection or oval ring heavy doping collector electrode.

17., it is characterized in that the external diameter R of described annular heavy doping collector electrode according to claim 15 or 16 described SOI high pressure LIGBT devices ₁With internal diameter R ₂Satisfy relation: $\frac{{R_2}^2}{{R_1}^2}=\frac{\mathrm{qN}(t_{\mathrm{Si}}-x_j)}{{\mathrm{\&epsiv;}}_{\mathrm{Si}}{E}_m},$ Wherein q is an elementary charge, and N is the drift region doping content, t _SiBe drift region thickness, x _jBe the junction depth of collector electrode, ε _SiBe the dielectric constant of silicon, E _mIt is the critical breakdown electric field of silicon.

18., it is characterized in that the ring medial region of described annular heavy doping collector electrode is and the opposite heterogeneous doped region (9) of drift region (2) doping according to claim 15 or 16 described SOI high pressure LIGBT devices.

19., it is characterized in that the ring medial region of described annular heavy doping collector electrode is and the identical zone of drift region (2) doping according to claim 15,16 or 17 described SOI high pressure LIGBT devices.

20., it is characterized in that the ring medial region of described annular heavy doping collector electrode is an insulating regions according to claim 15,16 or 17 described SOI high pressure LIGBT devices.

21. SOI high pressure LIGBT device according to claim 18 is characterized in that described heterogeneous doped region (9) extends longitudinally to inside, drift region (2), extends laterally to the external diameter R that is no more than annular heavy doping collector electrode ₁Scope.

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