TW201212228A - Heterojunction Bipolar Transistor structure with GaPSbAs base - Google Patents

Abstract

A heterojunction bipolar transistor (HBT) structure with a GaPSbAs base layer is disclosed. The HBT structure generally includes a substrate, a subcollector layer, a collector layer, a base layer, an emitter layer, an emitter cap layer, and a contact layer laminated from bottom to top sequentially, and optionally may further comprise a buffer between the substrate and the subcollector layer. The subcollector layer includes heavily doped GaAs; the collector layer includes one of GaAs, InGaP, and AlGaAs or their combinations; the base layer includes GaPSbAs compound; the emitter layer includes InGaP or AlGaAs; the emitter cap layer includes GaAs; the contact layer includes InGaAs; and the substrate includes semi-insulating GaAs. Since the base with GaPSbAs compound has lower band gap energy, the turn-on voltage of the transistors can be reduced. Furthermore, the GaPSbAs can form a type II band alignment with InGaP and AlGaAs emitters, the potential spike of the conduction band at the emitter-base interface is eliminated and thus further reduces the turn-on voltage of the transistors and reduces power consumption. As a result of the type II band alignment, the collector layer can be InGaP, or AlGaAs and other wide band gap materials, which increases the breakdown voltage and reduces the offset voltage and hence improves the power performance of the transistors.

Description

201212228 VI. Description of the Invention: [Technical Field] The present invention relates to a Heterojunction Bipolar Transistor (HBT) structure, particularly a base layer having gallium, phosphorus, and antimony. [Prior Art] A heterojunction bipolar transistor made of a group III-V element having a higher electron mobility (Mobility) than a field-Effect Transistor which is generally based on germanium ( HBT), for high-frequency signals, such as l_xin band (]-2GHz), C-band (4_8GHz) or higher frequency band, with lower distortion amplification characteristics and higher power, especially wireless communication devices Medium Power Amplifier (PA) for general use in handheld communication devices, such as mobile phones. Heterojunction bipolar transistors mainly use the emitter and base of different semiconductor materials to form a heterojunction at the junction of the emitter and the base due to the discontinuity of the valence band energy (AEV). By reducing the flow of the base to the emitter, the emitter efficiency (Emitter Injecti〇n Efficiency) and current gain can be obtained. The turn-on voltage of the HBT (Tum_〇n v〇ltage) • It is determined by the energy gap of the base material and the conduction band discontinuity (aEc) of the emitter-base junction, which plays an important role in the power consumption of the component. Therefore, when the base energy gap and the conduction band are discontinuous (Δ£; the lower the 〇, the lower the power consumption of the component, and the longer the life of the battery. The semiconductor materials that are extremely daring to hang are the indium phosphide money respectively. (nGaP) and gallium arsenide (GaAs) have the advantages of high power and high linearity. However, the use of a large base energy gap (142 eV at room temperature) is a disadvantage of stone as a base material. It is impossible to save f. In addition, because the Kunhua recorded blood wide-gap material such as indium gallium phosphide and aluminum gallium arsenide form the first type of energy band alignment, because of the wide bandgap material to improve the collapse of electricity 1, because The current collector U and the current blocking effect (c〇llect〇r Current Blocking Effect) occur, and the 201212228 ΐϊϊί pressure (〇ffset Vdtage)' can not improve the bipolar electrical performance of the heterojunction. Therefore, a base is needed. A heterojunction bipolar transistor structure with a small energy gap and a wide energy collector to increase the breakdown voltage is used to solve the above-mentioned problems of the prior art. [Summary of the Invention] The main purpose of the invention is to provide a kind of gallium The heterogeneous connection of the base and the crystal structure, The substrate, the sub-collector dipole layer, the layer, the emitter layer, the emitter cap layer and the contact layer are sequentially stacked from bottom to top, and V: selectively includes between the substrate and the sub-collector layer Buffer layer, 1 collector layer includes heavily doped yttrium-type gallium arsenide, collector layer includes deuterated gallium, g indium gallium phosphide or bribe and the three semiconductors, base layer compound, hetero layer package (4) Indium gallium is used for her gallium, and the emitter is covered with 申 ϋ 申 申 申 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 The lower energy gap of the kikon gamma, and the lower electron affinity than the phosphating ruthenium, which can reduce the conduction of the transistor. In addition, the gap material is used as the heterojunction bipolar in the month b. Electricity can therefore increase the breakdown voltage. Further, since the set 4 and the body; = ^ indium gallium do _ into, so that the hetero-base pavement and the base-collector junction material structure, so Lin low HBT compensation [Embodiment] The following is a description of the implementation of the invention and the components of the invention. After reading the book, you can implement it according to the text. > Read the figure - Figure 'The present invention has a gallium; a schematic diagram of the heterojunction bipolar crystal (HBT) structure of the transition base. As shown in the first figure, The sub-collector layer, the collector layer 40, the base layer 50, the emitter layer 6〇, and the emitter contact layer (10) are sequentially stacked from bottom to top on the 2G plate of the county plate of the county of Gallium, and the substrate 2G includes half. Insulation (semi_insulating9, SI) = 201212228 gallium (GaAs), sub-collector layer 30 includes heavily doped N-type gallium arsenide ^ + d〇ped GaAs), collector layer 40 includes N-type gallium arsenide, N-type phosphorus One of the indium gallium (InGaP) or N-type aluminum gallium arsenide (AlGaAs) or a combination of the three semiconductors, the base layer 50 includes a P-type gallium phosphide arsenic compound (the chemical formula is GaPxSb^yASy, and 〇< x$l '0$ y $0.1), one of the emitter layers including ^^-type indium gallium phosphide and Shi Shenhua Ming Su, the emitter cover layer 7〇 includes N-type gallium antimonide, n, Ion gallium One of (InGaP) or N-type bismuth gallium (A1GaAs) or a combination of the three semiconductors, and the contact layer 80 includes N-type indium gallium arsenide. The present invention is characterized in that the base layer 50 of the present invention has a lower energy than the base layer composed of gallium arsenide, in the structure of the present invention, using a gallium phosphonium arsenide compound (GaPxSbixyA). Band Gap Energy, which is the conduction band energy and the valence band energy (Valence Band)

The energy difference between Energy' can therefore reduce the turn-on voltage required for the HBT structure. Another feature of the present invention is that, according to the HBT structure of the present invention, the composition of the S and the gallium-labeled arsenic compound (^aPxSbkyASy) of the base layer 5〇 can be made such that the base layer 50 can form a collector. The material of the layer, that is, one of == gallium, indium gallium phosphide, and aluminum gallium arsenide, forms a second type of π) band alignment, that is, the conduction band energy of the base layer% is higher than The conduction band energy of arsenic ϊ 家 L phosphide or gallium arsenide, and the valence band energy of the base layer 50 is also higher than the valence band energy of gallium arsenide, indium gallium phosphide or aluminum gallium arsenide. Therefore, the collector layer 40 can no longer be limited to using only gallium antimonide, but a wide energy material such as indium gallium phosphide or aluminum gallium arsenide can be used without a collector current blocking effect. At the same time, compared with the same thickness and doping-rich sillimanite gallium collector layer, the wide-gap collector layer 4 of the present invention has a higher breakdown voltage which is higher than the high voltage operation. The lion of Ming Ming is based on the fact that it can increase the 4 impurity concentration in the wide layer of the collector layer to improve the Krk effect (leg Ε _) and the Ruggedness of the input. In addition, the collector layer of the present invention can use a thinner wide bandgap material to increase the cutoff frequency of the heterojunction (Cutoff Frequency) (Compared with the (4) chevron layer having the associated collapse voltage. ). Another advantage is that the = pole layer will cause the collector layer to become a depletion zone, and the guide set of the second (four) / μ valley (BaSe_C〇丨丨ector Juncti〇n Capacitance) will not further follow the bias voltage. Enhancing the linearity of a heterojunction bipolar transistor. The gallium-phosphorus bipolar junction bipolar transistor structure 10 30 includes a buffer layer (not shown) on the substrate 20 and the secondary collector. The layer of Gu·^^ 1 is only a ribbed touch of the invention to read Jiashiguan, not an attempt to restrict the lyrics of 'the invention, any invention or any modification or modification of the invention' should still be included in this [Simplified description of the figure] Body knot ^^ Invented heterogeneous junction bipolar electro-crystals with different bases [Major component symbol description] 10 Heterojunction bipolar transistor (ΗΒΤ) structure 20 substrate 30 sets Polar layer 40 collector layer 50 base layer 60 emitter layer 70 emitter cover layer 80 contact layer

Claims (1)

201212228 VII. Patent application scope: 1.- A bipolar transistor structure with a heterojunction of a gallium Lion's base, comprising: a substrate; a collector layer stacked on the substrate; a layer stacked on the layer On the collector layer, the p-type slant compound is represented by the chemical formula GaPxSb-Asy and 〇 χ 〇 〇 〇丨 〇丨 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 以及 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 —· 2. According to the heterojunction bipolar transistor structure described in the first application of the special machine, the step-by-step collector layer is stacked between the substrate and the collector layer, and includes the re-doping Hetero N-type gallium arsenide. The heterojunction bipolar transistor structure according to the item 1, wherein the substrate i includes semi-insulating (GaAs). i 依 ϋ ϋ ϋ ϋ ϋ 第 第 第 第 第 第 第 第 Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ - or a combination of the yttrium-corrected gallium, the scorpion-type squamous ingot, and the bismuth-type aluminum arsenide. The heterozygous double-difficult crystal structure described in the above-mentioned item, wherein the 4 emitter layer comprises N (tetra) indium The structure of gallium and N (four) yin gallium, the further steps include: stacking i the base