摘要:
The invention relates to a method of manufacturing implanted-base, double polysilicon bipolar transistors whose emitter, base and collector are all situated in a single active area. In accordance with the method, first the island isolation (3) defining the active area (4) in the silicon body (1) is provided, which active area forms the collector (5). A first polysilicon layer (6) is deposited on the surface. A first part (6a) of poly I is p-type doped, a second part is n-type doped. By etching, two separate parts are formed from the first poly layer, one part being p-type doped and forming a base terminal (8), the other part being n-type doped and forming a collector terminal (9), said two parts being separated by an intermediate region (16) where the surface of the active area is exposed. The edges of these poly terminals and the exposed parts of the active area are provided with spacers (13, 15) and spacers (14, 16), respectively. After the provision of the intrinsic base region (11), a non-walled emitter (19) and the emitter terminal (18) in the form of an n-type doped second poly layer are provided in said intermediate region between the base and collector-terminals.
摘要:
A method of manufacturing a semiconductor device comprising heterojunction bipolar transistors (HBTs), in which method a first semiconductor layer of monocrystalline silicon (5), a second semiconductor layer of monocrystalline silicon comprising 5 to 25 at. % germanium (6) and a third semiconductor layer of monocrystalline silicon (7) are successively provided on a surface (2) of a silicon wafer (1) by means of epitaxial deposition. Base zones of the transistors are formed in the second semiconductor layer. In this method, the second semiconductor layer is deposited without a base doping, said doping being formed at a later stage. Said doping can be formed by means of an ion implantation process or a VPD (Vapor Phase Doping) process. This method enables integrated circuits comprising npn-transistors as well as pnp-transistors to be manufactured.
摘要:
A method of manufacturing a semiconductor device with an epitaxial semiconductor zone, whereby a first layer of insulating material, a first layer of non-monocrystalline silicon, and a second layer of insulating material are provided in that order on a surface of a silicon wafer, a window with a steep wall is etched through the second layer of insulating material and the first layer of non-monocrystalline silicon, the wall of the window is provided with a protective layer, the first insulating layer is selectively etched away within the window and below an edge of the first layer of non-monocrystalline silicon adjoining the window such that both the edge of the first layer of non-monocrystalline silicon itself and the surface of the wafer become exposed within the window and below said edge, semiconductor material is selectively deposited such that the epitaxial semiconductor zone is formed on the exposed surface of the wafer, and an edge of polycrystalline semiconductor material connected to the epitaxial semiconductor zone is formed on the exposed edge of the first layer of non-monocrystalline silicon, an insulating spacer layer is provided on the proctective layer on the wall of the window, and a second layer of non-monocrystalline silicon is deposited. The provision of a top layer of a material on which non-monocrystalline semiconductor material will grow during the selective deposition of the semiconductor material, which top layer is provided on the second layer of insulating material before the selective deposition of the semiconductor material, achieves that the selective deposition process can be better monitored.
摘要:
The bipolar transistor comprises a collector region (1) of a semiconductor material having a first doping type, a base region (2) of a semiconductor material having a second doping type, and an emitter region (3) having the first doping type. A junction is present between the emitter region (3) and the base region (2), and, viewed from the junction (4), a depletion region (5) extends into the emitter region (3). The emitter region (3) comprises a layer (6) of a first semiconductor material and a layer (7) of a second semiconductor material.The first semiconductor material has a higher intrinsic carrier concentration than the second semiconductor material. The layer (7) of said second semiconductor material is positioned outside the depletion region (5). The second semiconductor material has such a doping concentration that Auger recombination occurs.The invention also relates to a semiconductor device comprising such a bipolar transistor.The method of manufacturing the bipolar transistor comprises the step of forming an emitter region (3) with a first doping type on a collector region (1) of a semiconductor material with a first doping type, and a base region (2) of a semiconductor material having a second doping type. The emitter region (3) is formed by epitaxially depositing a first layer (6) of a first semiconductor material and subsequently epitaxially depositing a second layer (7) of a second semiconductor material. The second layer (7) is doped with the first doping type, such that Auger recombination occurs. The intrinsic carrier concentration of the second semiconductor material is higher than the intrinsic carrier concentration of the first semiconductor material.The Auger recombination dominates the base current and allows accurate tuning of the base current and the current gain of the bipolar transistor.
摘要:
The bipolar transistor comprises a collector region (1) of a semiconductor material having a first doping type, a base region (2) of a semiconductor material having a second doping type, and an emitter region (3) having the first doping type. A junction is present between the emitter region (3) and the base region (2), and, viewed from the junction (4), a depletion region (5) extends into the emitter region (3). The emitter region (3) comprises a layer (6) of a first semiconductor material and a layer (7) of a second semiconductor material. The first semiconductor material has a higher intrinsic carrier concentration than the second semiconductor material. The layer (7) of said second semiconductor material is positioned outside the depletion region (5). The second semiconductor material has such a doping concentration that Auger recombination occurs. The invention also relates to a semiconductor device comprising such a bipolar transistor. The method of manufacturing the bipolar transistor comprises the step of forming an emitter region (3) with a first doping type on a collector region (1) of a semiconductor material with a first doping type, and a base region (2) of a semiconductor material having a second doping type. The emitter region (3) is formed by epitaxially depositing a first layer (6) of a first semiconductor material and subsequently epitaxially depositing a second layer (7) of a second semiconductor material. The second layer (7) is doped with the first doping type, such that Auger recombination occurs. The intrinsic carrier concentration of the second semiconductor material is higher than the intrinsic carrier concentration of the first semiconductor material. The Auger recombination dominates the base current and allows accurate tuning of the base current and the current gain of the bipolar transistor.
摘要:
The invention relates to the manufacture of a so-called differential bipolar transistor comprising a base (1A), an emitter (2) and a collector (3), the base (1A) being formed by applying a doped semiconducting layer (1) which locally borders on a monocrystalline part (3) of the semiconductor body (10) where it forms the (monocrystalline) base (1A), and which semiconducting layer (1) borders, outside said monocrystalline part, on a non-monocrystalline part (4, 8) of the semiconductor body (10) where it forms a (non-monocrystalline) connecting region (1B) of the base (1A). The non-monocrystalline part (4, 8) of the semiconductor body (10) is obtained by covering the semiconductor body (10) with a mask (20) and replacing on either side thereof a part (8) of the semiconductor body (10) by an electrically insulating region (8) and by providing this, prior to the application of the semiconducting layer (1) with a polycrystalline semiconducting layer (4). The known method, in which an aperture is etched above the collector (3) after deposition of the polycrystalline layer (4), is relatively laborious. In a method in accordance with the invention, the polycrystalline layer (4) is selectively provided on the electrically insulating region (8), in which process use is made of the mask (20) to form the electrically insulating region (8). This method is less laborious than the known method. In addition, the resultant transistors have excellent properties and their dimensions may be very small. Preferably, both in the manufacture of the insulating region (8), preferably an oxide-filled groove (8), and in the process of selectively applying the polycrystalline layer (4) to the insulating region, use is made of a deposition step followed by a chemico-mechanical polishing step.
摘要:
The invention relates to a method of manufacturing a discrete or integrated bipolar transistor comprising a base (1A), an emitter (2) and a collector (3). The base (1A) and a connecting region (1B) of the base (1A) are formed by providing a semiconductor body (10) with a doped semiconducting layer (1) which locally borders on a monocrystalline part (3) of the semiconductor body which forms the collector (3). Outside said base, the layer (1) borders on a non-monocrystalline part (4) of the semiconductor body (10) and forms a non-monocrystalline connecting region (1B) of the base (1A). By means of a mask (5), the doping concentration of the layer (1) outside the mask (5) is selectively increased, resulting in a highly conducting connection region (1B) and a very fast transistor. In the known method, an ion implantation is used for this purpose. In a method in accordance with the invention, this is achieved by bringing the semiconductor body (10) into contact with a gaseous substance (40) comprising a doping element, and heating the semiconductor body (10) in such a manner that the doping elements penetrate into the semiconducting layer (1). Such a method surprisingly results in a much faster transistor. It has been found that this enables, on the one hand, a much smaller diffusion in the thickness direction of the doping of the base (1A) to be achieved, which results in a much faster transistor, particularly, if the base (1A) contains SiGe. On the other hand, the lateral diffusion from the connecting region (1B) to the base (1A) is particularly strongly suppressed. This too has a beneficial effect on the speed of the transistor. The supply of the gaseous substance (40), for example diborane, preferably takes place at a temperature between 800 and 950.degree. C. for one to several minutes. Subsequently, a slightly longer diffusion step can be carried out, for example, at 850.degree. C.