KR20020015822A - stacking verticality style for Monolithic Microwave Integrated Circuit - Google Patents

Abstract

PURPOSE: A vertically-stacked monolithic microwave integrated circuit is provided to reduce an occupying volume by vertically stacking silicon wafers on a circuit board, and to increase an operation frequency by fabricating the silicon wafer by using silicon-on-insulator(SOI). CONSTITUTION: A plurality of upper and lower silicon wafers are formed on and under an oxide layer. A plurality of upper and lower polysilicon layers are deposited on a partial upper surface of the upper silicon wafer and on the entire lower surface of the lower silicon wafer by a predetermined thickness. A barium strontium titanate(BST) layer composed of barium and strontium is deposited on the lower surface of the lower silicon wafer to prevent power consumption. An oxide layer is formed on the lower surface of the BST layer and on the upper polysilicon layer. Upper and lower metal layers are made of a metal material. Solder balls(16a,16b) are connected to the metal layers. The solder ball of the upper metal layer is interconnected by a wire, and the solder ball of the lower metal layer is directly interconnected. An electrical signal can be transferred according to a circuit pattern formed on the surface of the circuit board(18).

Description

Stacking verticality style for Monolithic Microwave Integrated Circuit

The present invention relates to a vertically stacked monolithic microwave integrated circuit, and more particularly, by stacking silicon wafers vertically and vertically on a circuit board to reduce the volume, to enable a large-capacity one-chip design and to use a silicon wafer using SOI. The present invention relates to a vertically stacked monolithic microwave integrated circuit capable of improving operating frequency and reducing power consumption.

The main electronic devices of the general radar include a receiver and a transmitter. The radar receiver consists of an RF stage that receives a microwave input signal and converts it into an IF stage, and an IF stage that performs signal processing at a low frequency. The RF stage consists of a low noise amplifier (LNA), a mixer, a voltage-controlled oscillator (VCO), and the conventional microwave circuits are mainly hybrid.

In the 1980s, however, with the rapid development of microwave technology, hybrid microwave circuits were gradually replaced by monolithic microwave integrated circuits.

Monolithic microwave integrated circuitry of radar components has spread to not only receiver components but also transmitter components in recent years. Radar transmitters generally require large outputs, so in the past they have used magnetrons, cristrons, and traveling wave tubes (TWTs), but because of reliability problems, solid state SSPAs using semiconductors The use of power amplifiers is increasing. In the 1990s, SSPA is also actively progressing from hybrid to monolithic microwave integrated circuit.

The monolithic microwave integrated circuit (MMIC) is an application component of compound semiconductors, which is rapidly expanding in the mobile communication device market, and has excellent high frequency characteristics, little change in characteristics according to signal size, and RF. It is an information communication component that enables the integration of several devices in a single chip, and is one of the most promising communication components in the future.

Monolithic microwave integrated circuits are the core technology of microwave systems that are expanding their use as RF components for satellite and mobile communication as well as radar.

The general process of manufacturing a monolithic microwave integrated circuit is as follows.

First, the first metal used as the base plate of the capacitor is deposited on the substrate.

After that, Si3N4, SiO _2, etc., to be used as a dielectric is deposited to a thin thickness of several thousand angstroms by using a PECVD (Plasma Enhanced Chemical Vapor Deposition) method, and then a second metal used as a top plate of the capacitor is deposited. Finally, to connect the top plate and the planar feed structure, a three-dimensional connection structure, Airbridge, is manufactured.

In addition to capacitors, via holes, inductors, and resistors that connect the top and bottom of the substrate are fabricated on the substrate of active devices using this semiconductor integrated circuit process technology.

First of all, its size and weight are smaller than dozens or hundreds of times smaller than HMIC. Since the resolution of the photolithography using the semiconductor process is less than 1 (µm), the line width and the spacing between the lines can be reduced in micrometers.

For example, in the case of the microstrip line, the line width of the line having a characteristic impedance of 50 에 on the GaAs having a thickness of 100 μm is about 50 μm, which is much thinner than the general case of the HMIC. Used in

The reduction of line width and line spacing leads to chip reduction, and the size of a typical monolithic microwave integrated circuit low noise amplifier is about several millimeters (mm2) and about tens of millimeters (mm2) of power amplifier. . In the case of mobile phones, such as light weight and small amount is being developed, the demand for monolithic microwave integrated circuits with small chip size is expected to increase.

The monolithic microwave integrated circuit refers to a circuit form in which all active devices and passive devices are implemented on one substrate, as shown in FIG. 1.

As shown in FIG. 1, in the conventional monolithic microwave integrated circuit, silicon wafers 2 and 8 are connected to left and right sides on one circuit board 1, and the left silicon wafer 2 is surrounded. The polysilicon layer (3) is laminated on the top plate (4) of metal material and then bonded to the solder ball (5) and the wire (6) on the top plate 4 to form an active element and the right side of the active element The wire 6 is bonded to the upper surface of the silicon wafer which is in surface contact with the circuit board, and the oxide film and the metal plate are laminated on the upper surface, and then the solder ball and the wire are bonded to the circuit board so that the passive element is made. It consists of a configuration that can implement an RF device.

However, these conventional monolithic microwave integrated circuits connect active and passive elements horizontally to each other individually on a single substrate, thereby increasing the overall volume, thereby increasing the difficulty of high-density circuit design and structural design cost. In this case, since a wire must be connected as long as the distance formed between the active element and the passive element, a capacitor is formed on the wire, which has a problem of degrading power loss and frequency characteristics.

The present invention is intended to solve such problems in the related art, and its purpose is to stack silicon wafers vertically and vertically on a circuit board to reduce the volume, thereby enabling a large-capacity one-chip design and manufacturing silicon wafers using SOI. Therefore, the operating frequency is to improve and reduce the power consumption.

1 is a cross-sectional view of a conventional horizontal monolithic microwave integrated circuit.

2, 3, 4, 5, and 6 are schematic diagrams of a manufacturing process of a vertically stacked monolithic microwave integrated circuit according to an exemplary embodiment of the present invention.

Code descriptions for the main parts of the drawings

1,18; circuit board 2, 11a, 11b; silicon wafer

3,13a, 13b; polysilicon layer 4; top plate

5,16a, 16b; Solder Ball 6,17; Wire

12; oxide layer 14; BESTI layer

15a, 15b; metal film layer

Hereinafter, the technical configuration of the present invention with reference to the accompanying drawings in detail.

The present invention relates to a structure for stacking a monolithic microwave integrated circuit device up and down, as shown in Figures 2 to 6 a plate having a predetermined thickness formed on the top or bottom exposed to the center and the outside to form And a plurality of upper and lower silicon wafers 11a and 11b on which upper and lower portions of the oxide film layer 12 are plated with ions implanted thereon to prevent foreign substances from being introduced and to facilitate electrical signal transmission. A plurality of upper and lower polysilicon layers 13a and 13b deposited on a portion of the upper surface of the upper silicon wafer 11a and deposited to a predetermined thickness on the entire lower surface of the lower silicon wafer 11b and the lower polysilicon 13b. A barium strontium titanate (BST) layer 14 formed by mixing barium and strontium so as to be deposited on the lower surface of the layer to prevent power loss; Upper and lower metal film layers formed of an oxide film formed on the bottom surface of the tee layer 14 and the top surface of the upper polysilicon layer 13a to prevent foreign substances from being introduced and to allow electrical signals to be transferred to each other. 15a, 15b, solder balls 16a and 16b connected to the metal film layers 15a and 15b to allow an electrical signal to be transmitted to the outside, and solder balls of the metal film layer 15a. The circuit board 18 connects the wires 17 between the wires 16a and the direct connection between the solder balls 16b of the metal film layer 15b so that electrical signals can be transferred to each other according to a circuit pattern formed on the surface. It is connected and made up.

A method for manufacturing a monolithic microwave integrated circuit device of the present invention is stacked up and down, as shown in Figures 2 to 6 by forming a plate having a predetermined thickness on the upper or lower portion exposed to the center and the outside A plurality of upper and lower silicon wafers 11a and 11b in which ions are injected are deposited on the upper and lower ends of the oxide layer 12 to prevent external foreign substances from being introduced and to facilitate electrical signal transmission. To deposit a portion on the upper surface of the upper silicon wafer (11a) and to deposit a plurality of upper and lower polysilicon layers (13a, 13b) of a predetermined thickness on the entire lower surface of the lower silicon wafer (11b), the lower poly A barium strontium titanate (BST) layer formed by mixing barium and strontium to form a layer to be deposited on the bottom surface of the silicon 13b layer to suppress power loss. 14) may be stacked, and upper and lower metal film layers 15a and 15b formed of an oxide film or a metal material may be deposited on the bottom surface of the BST layer 14 and the top surface of the upper polysilicon layer 13a. The solder ball 16 may be bonded to the metal film layers 15a and 15b to allow an electrical signal to be transmitted to the outside, and the wires 17 may be connected between the solder balls of the metal film layer 15a. By mounting the solder ball surface of the metal film layer (15b) to have a configuration of the manufacturing method for connecting to the circuit board 18 so that the electrical signal can be transferred to each other according to the circuit pattern formed on the surface.

Referring to the effects of the present invention configured in this way in detail as follows.

The present invention is to stack the active element and passive element of the monolithic micro external integrated circuit up and down, and as shown in Figure 2a, two silicon wafers (11a) (11b) formed by implanting ions as an oxide film formed of an oxide The layer 12 is deposited on the top and the bottom, and particularly, the parts exposed to the outside are laminated to prevent the inflow of foreign substances while smoothly transmitting the electrical signals.

The silicon wafers 11a and 11b may be stacked vertically and bonded to the oxide layer 12 to prevent carrier electrons from moving upward and downward through the oxide layer 12 and to diffuse the silicon on insulator (SOI). By using it has the effect of increasing the operating frequency and low power.

Thereafter, the upper and lower silicon wafers 11a and 11b are formed of at least 1 to 2 micrometers of polysilicon 13a and 13b on the upper and lower end surfaces of the upper and lower silicon wafers 11a and 11b, as shown in FIGS. 2B and 2C. ) To prevent the loss of power by stacking the BEST layer 14 having a thickness of 2) and forming a film by mixing barium and a streak on the lower polysilicon 13b.

On the other hand, the silicon wafers 11a and 11b are formed on the upper and lower silicon wafers 11a and 11b, respectively, by the oxide film or the metal film layers 15a and 15b, respectively, to transfer electrical signals to the outside. By depositing, electrical signals can be transferred between the silicon wafers 11a and 11b and the external electric devices.

Finally, the silicon wafers 11a and 11b bond the wires 17 to the metal film layer 15a deposited on the upper silicon wafer 11a in order to transfer electrical signals to the circuit board 18. 18) and the solder ball (16a) to bond the electrical signal to each other, the lower silicon wafer (11b) is bonded to the solder ball (16b) to be directly bonded to the circuit board 18, the electrical signal Since it can be transferred to each other to reduce the seating area of the silicon wafer stacked on the circuit board up and down, it can be made in one chip, and the silicon wafer is used as the SOI, so the operating frequency is increased and can be operated at low power.

The present invention, which acts as above, reduces the volume by stacking silicon wafers vertically and vertically on a circuit board, thereby enabling a large-capacity one-chip design and manufacturing silicon wafers using SOI, thereby improving operating frequency and reducing power consumption. It has an effect so that.

Claims (2)

In the highly integrated monolithic microwave integrated circuit, an oxide film which forms a plate having a predetermined thickness on the upper part or the lower part exposed to the center and the outside to prevent the inflow of foreign substances from the outside and at the same time facilitate the electrical signal transmission. A plurality of upper and lower silicon wafers 11a and 11b on which upper and lower plates of the layer 12 are implanted are deposited, and a lower silicon wafer 11b is deposited on a portion of the upper surface of the upper silicon wafer 11a. ) Is deposited on the bottom and bottom of the plurality of upper and lower polysilicon layers (13a, 13b) and the lower polysilicon (13b) layer is deposited on the entire lower surface of the barium and strontium to prevent power loss BST (barium strontium titanate) layer 14, which is mixed and deposited as a layer, is formed on the bottom surface of the BST layer 14 and the upper surface of the upper polysilicon layer 13a to prevent foreign substances from entering. At the same time, a layer of an oxide film that allows electrical signals to be transferred to each other or a metal material layer 15a and 15b at upper and lower ends formed of a metal material and connected to the metal film layers 15a and 15b to be electrically connected to the outside. The wires are connected between the solder balls 16 and the solder balls of the metal layer 15a to directly transmit signals, and the solder balls 16 are directly connected to the solder balls of the metal layer 15b. A vertically stacked monolithic microwave integrated circuit structure in which circuit boards (18) are connected to each other so that signals can be transmitted to each other. In the manufacturing method for stacking a monolithic microwave integrated circuit device up and down, a plate having a predetermined thickness is formed on the top or bottom exposed to the center and the outside to prevent the inflow of foreign matters and at the same time to transmit the electrical signal A plurality of upper and lower silicon wafers 11a and 11b in which ions are implanted are deposited on upper and lower portions of the oxide layer 12 so as to be smoothly formed, and deposited on a portion of an upper surface of the upper silicon wafer 11a. And a plurality of upper and lower polysilicon layers 13a and 13b having a predetermined thickness are deposited on the entire lower surface of the lower silicon wafer 11b, and is deposited on the lower surface of the lower polysilicon 13b layer to suppress power loss. The barium strontium titanate (BST) layer 14 may be stacked by mixing barium and strontium, and the bottom surface of the BST layer 14 may be stacked. The upper and lower metal film layers 15a and 15b formed of an oxide film or a metal material may be deposited on the upper surface of the upper polysilicon layer 13a, and an electrical signal may be applied to the metal film layers 15a and 15b. A circuit formed on the surface to allow the solder ball 16 to be bonded to be transferred, the wire 17 between the solder ball of the metal film layer 15a to be seated and the solder ball surface of the metal film layer 15b to be seated. Method for manufacturing a vertically stacked monolithic microwave integrated circuit formed by connecting to a circuit board (18) so that electrical signals can be transmitted to each other according to the pattern.