Integrated gate commutated thyristor and manufacture method thereof
Technical field
The present invention relates to the power semiconductor device technical field, particularly a kind of high-power integrated gate commutated thyristor (IGCT).
Background technology
IGCT (Integrated Gate Commutated Thyristor) is called integrated gate commutated thyristor.It is a kind of novel high-power power semiconductor device that developed recently gets up.IGCT be with numerous door pole stream-exchanging thyristors (GCT) by printed circuit board and gate-drive device be linked to be one integrally formed.IGCT is four layers of three terminal device, and its inside is made up of thousands of GCT sliver.IGCT makes usually against leading type, and the anode of its fly-wheel diode and the gate pole of GCT are shared, and the negative electrode sliver of GCT is connected in parallel, and is integrated on the same chip with the fly-wheel diode monolithic.Against the structure of leading type door pole stream-exchanging thyristor GCT as shown in Figure 1, Fig. 1 is existing contrary section of structure of leading the elementary cell of GCT.This figure left side is GCT, and the right side is the inverse parallel diode.GCT is one five layers a PNN-PN+ thyristor, and wherein the PNN-PN+ thyristor adopts many negative electrodes sliver parallel-connection structure.The N district of GCT is made up of n-base and n resilient coating two parts, and anode 16 is connected to transparent anode district, p+ district, and p base 20 connects gate pole 10, and the n+ district connects negative electrode 11.The right of GCT is the PN-N diode section, and anode 16 is shared with the negative electrode of PN-N diode, and promptly anode 16 also is the negative electrode of PN-N diode, and the p base 21 of PN-N diode connects the anode 15 of diode.The negative electrode 11 of GCT and the anode of diode 15 are electrically connected by peripheral circuit.
Need to have effective isolation between GCT and the diode, GCT and diode are enjoyed same blocking-up knot (pn-) among Fig. 1, therefore be to utilize the pn knot to isolate between the p base 21 of the p base 20 of GCT and diode, its equivalent electric circuit is equivalent to be connected with two diodes of differential concatenation as shown in Figure 2 between negative electrode K and the gate pole G.But under high pressure there is the difficulty of terminal processes in the high voltage junction body in this isolation method.
Fig. 3 is the another kind of section of structure of existing GCT elementary cell.As shown in Figure 3, in the isolation method of this structure, form isolated groove 25 by the etching technics etching in the public p base of GCT on the n base and diode, the volume resistance of utilizing the isolated groove after the etching to form in the p base realizes the isolation of GCT and diode, its equivalent electric circuit as shown in Figure 4, R
GKBe the body isolation resistance between gate pole G and the negative electrode K.Yet in this mode, because will reaching tens microns ability usually, gash depth obtains suitable isolation resistance, and etching dark groove like this implements very difficulty for etching technics, and is difficult to etching depth is accurately controlled, and easily makes the isolation resistance R of formation
GKResistance too small.Too small isolation resistance R
GKCan cause the turn-on and turn-off electric current that adds, increase the turn-on and turn-off loss.
Summary of the invention
The object of the present invention is to provide a kind of integrated gate commutated thyristor and manufacture method thereof, can between GCT unit and diode, realize effective isolation.
A kind of integrated gate commutated thyristor, described door pole stream-exchanging thyristor comprises n
-The type substrate, p type doped region, n type doped region, the anode p+ doped region of door pole stream-exchanging thyristor, diode n+ buffering area, and the negative electrode sliver of door pole stream-exchanging thyristor also comprise the negative electrode and the gate pole of door pole stream-exchanging thyristor, the negative electrode of the anode of diode, the anode of door pole stream-exchanging thyristor and diode is characterized in that: have n+ type shading ring in the p type doped region between the anode of the gate pole of door pole stream-exchanging thyristor and diode.
The n type foreign ion that injects in the described n+ type shading ring district be among phosphorus, arsenic, antimony, bismuth or the nitrogen any one or multiple.
The concentration of described n type foreign ion is 1E17/cm
3~1E19/cm
3
Described n
-The doping impurity concentration of type substrate is 1E11/cm
3~1E13/cm
3
The impurity concentration of described p type and n type doped region is at 1E14/cm
3~1E18/cm
3
The concentration of the foreign ion of described p+ doped region and n+ buffering area is 1E17/cm
3~1E20/cm
3
Correspondingly, the present invention also provides a kind of manufacture method of integrated gate commutated thyristor, comprising:
One n is provided
-The type monocrystalline substrate;
At described n
-The two-sided diffusion of impurities of carrying out of type substrate forms p type doped region and n type doped region;
Annular region between GCT district and diode region forms n
+The annular isolation district;
Upper surface and lower surface at described substrate form the n+ doped region;
In the n of described substrate lower surface type doped region, form the p+ doped region;
Form the negative electrode sliver of GCT;
Form the electrode of GCT and diode.
N type foreign ion in the described n+ annular isolation district be among phosphorus, arsenic, antimony, bismuth or the nitrogen any one or multiple.
The concentration of described n type foreign ion is 1E17/cm
3~1E19/cm
3
The impurity concentration of described p type and n type doped region is at 1E14/cm
3~1E18/cm
3
The concentration of the foreign ion of described p+ doped region and n+ buffering area is 1E17/cm
3~1E20/cm
3
Compared with prior art, the present invention has the following advantages:
Integrated gate commutated thyristor of the present invention utilizes n type doping impurity ring isolation structure between the GCT district of substrate and diode region, realize the isolation between GCT and the diode.The formation of n type doping impurity ring adopts common diffusion technology or ion implantation technology to form, and the junction depth of injection can be regulated according to existing technological level, and technology controlling and process is flexible, and technology realizes simple and easy to do.By regulating the technological parameter of n type doping impurity ring, can obtain the junction depth of wishing easily, thus the isolation resistance resistance that obtains expecting.The isolation resistance that is obtained by n type doping impurity ring structure has reduced the extra gate electrode current, has reduced the supplementary load loss of gate pole.Adopt n type doping impurity ring isolation structure gate pole extra current and supplementary load loss can be controlled at more suitable scope by regulating the isolation resistance size of junction depth acquisition expectation.
In addition, can suppress interfering with or disturb each other of minority carrier lifetime measured value between GCT unit and the diode, both electron irradiations all can independently be controlled by n type doping impurity ring isolation structure.
Description of drawings
By the more specifically explanation of the preferred embodiments of the present invention shown in the accompanying drawing, above-mentioned and other purpose, feature and advantage of the present invention will be more clear.Reference numeral identical in whole accompanying drawings is indicated identical part.Painstakingly do not draw accompanying drawing in proportion, focus on illustrating purport of the present invention.In the accompanying drawings, for cheer and bright, amplified the thickness in layer and zone.
Fig. 1 is existing contrary section of structure of leading the elementary cell of GCT;
Fig. 2 is contrary equivalent circuit diagram of leading the GCT elementary cell shown in Figure 1;
Fig. 3 is existing contrary another kind of section of structure of leading the GCT elementary cell;
Fig. 4 is contrary equivalent circuit diagram of leading the GCT elementary cell shown in Figure 3;
Fig. 5 to Figure 11 is the contrary device profile schematic diagram of leading type integrated gate commutated thyristor manufacture method of explanation according to the embodiment of the invention.
Embodiment
For above-mentioned purpose of the present invention, feature and advantage can be become apparent more, the specific embodiment of the present invention is described in detail below in conjunction with accompanying drawing.
A lot of details have been set forth in the following description so that fully understand the present invention.But the present invention can implement much to be different from alternate manner described here, and those skilled in the art can do similar popularization under the situation of intension of the present invention.Therefore the present invention is not subjected to the restriction of following public specific embodiment.
Fig. 5 to Figure 11 is the device profile schematic diagram of explanation according to the integrated gate commutated thyristor manufacture method of the embodiment of the invention.For for simplicity, only show the forming process of the basic GCT unit of IGCT among the figure.As shown in Figure 5, at first provide a monocrystalline substrate, this monocrystalline substrate is carried out n type doping impurity, the doping content of impurity is 1E11/cm
3~1E13/cm
3, be preferably 1E13/cm
3, obtain n
- Monocrystalline substrate 100 is hereinafter to be referred as n-type substrate 100.
Next as shown in Figure 6, the two-sided diffusion of impurities of carrying out at n-type substrate 100, promptly form p type doped region 110 at the upper surface diffusion p of n-type substrate 100 type impurity, lower surface at n-type substrate 100 utilizes the photoresist mask that the GCT district is carried out n type diffusion of impurities formation n type doped region 120, and the concentration of p type impurity and n type impurity is at 1E14/cm
3~1E18/cm
3Between, be preferably 1E15/cm
3
Subsequently, as shown in Figure 7, the annular region between GCT district and diode region is mixed in advance, and the n type foreign ion that injects higher concentration by diffusion forms annular isolation district 130.Specifically, utilize a mask, photoresist mask for example covers the p type doped region 110 of GCT district and diode region, exposes the annular region between GCT district and the diode region.Utilize diffusion or ion implantation technology in the above-mentioned annular isolation district of mask definition, to inject n type foreign ion then, any one among phosphorus, arsenic, antimony, bismuth or the nitrogen or multiple for example, the concentration of n type foreign ion alloy is 1E17/cm
3~1E19/cm
3, be preferably 1E18/cm
3Thereby form the annular isolation district 130 that n type foreign ion mixes.The junction depth that the n type foreign ion in above-mentioned annular isolation district 130 injects can be decided according to the required resistance of aforementioned isolation resistance, and the present invention does not do too much restriction, and those skilled in the art are decided by actual conditions.
Next as shown in Figure 8, in the p type doped region 100 of the upper surface of substrate 100, utilize mask to define base and annular isolation district, define the resilient coating of diode at the lower surface of substrate 100, proceed the n type doping impurity of higher dosage, concentration is 1E17/cm
3~1E20/cm
3, be preferably 1E18/cm
3, n+ base 150 and the darker annular isolation district 140 of junction depth of formation GCT, and the n+ resilient coating 160 of diode.
Then as shown in Figure 9, carry out the diffusion of GCT anode p type foreign ion in the n type doped region 120 of substrate 100 lower surfaces, form p+ doped region 170, the concentration of foreign ion is 1E17/cm
3~1E20/cm
3, be preferably 1E18/cm
3Utilize common process such as mask, etching, form the negative electrode sliver 151 of GCT, as shown in figure 10.The junction depth in the n+ annular isolation zone 141 after the etching is the difference of the junction depth and n+ base 150 junction depths in said n+annular isolation district 140, and the junction depth in n+ annular isolation zone 141 is preferably 40um in the present embodiment.
Adopt technologies such as physical vapor deposition, evaporation or sputter to form the negative electrode 180 of GCT, the gate pole 185 of GCT, the anode 190 of diode subsequently, and the anode of GCT (negative electrode of diode) 200, as shown in figure 11.
According to the integrated gate commutated thyristor of the embodiment of the invention also as shown in figure 11, described door pole stream-exchanging thyristor comprises n
-Type substrate 100, p type doped region 110, n type doped region 120, GCT anode p+ doped region 170, diode n+ buffering area 160, and GCT negative electrode sliver 151 also comprise the negative electrode 180 of GCT, the gate pole 185 of GCT, anode 190 and the anode of GCT and the negative electrode 200 of diode of diode, in addition, has n+ type shading ring 141 in the p type doped region 110 of door pole stream-exchanging thyristor of the present invention between the anode 190 of the gate pole 185 of GCT and diode.The isolation resistance that is obtained by n+ type shading ring 141 structures can reduce the extra gate electrode current, has reduced the supplementary load loss of gate pole.Wherein, the n type foreign ion that injects in the n+ type shading ring district be among phosphorus, arsenic, antimony, bismuth or the nitrogen any one or multiple.The concentration of n type foreign ion is 1E17/cm
3~1E19/cm
3n
-The doping impurity concentration of type substrate is 1E11/cm
3~1E13/cm
3The impurity concentration of p type and n type doped region is at 1E14/cm
3~1E18/cm
3The concentration of the n type foreign ion of p+ doped region and n+ buffering area is 1E17/cm
3~1E20/cm
3
Integrated gate commutated thyristor of the present invention is utilizing n+ type doping impurity to form the isolation that n+ type shading ring 141 is realized between GCT and the diode between the GCT district of substrate and the diode region.The formation of n+ type shading ring 141 adopts common diffusion technology or ion implantation technology to form, by regulating the technological parameter of diffusion or ion implantation technology, can obtain the junction depth of wishing easily, thereby the isolation resistance resistance that obtains expecting is controlled at more suitable scope with gate pole extra current and supplementary load loss.
Though the present invention discloses as above with preferred embodiment, yet be not in order to limit the present invention.Any those of ordinary skill in the art, do not breaking away under the technical solution of the present invention scope situation, all can utilize the method and the technology contents of above-mentioned announcement that technical solution of the present invention is made many possible changes and modification, or be revised as the equivalent embodiment of equivalent variations.Therefore, every content that does not break away from technical solution of the present invention, all still belongs in the scope of technical solution of the present invention protection any simple modification, equivalent variations and modification that above embodiment did according to technical spirit of the present invention.