SU865078A1 - Method of generating potential reliff in charge-coupled devices - Google Patents

Abstract

A METHOD FOR CREATING A POTENTIAL RELIEF IN THE DEVICES WITH A CHARGER CONNECTION in a semiconductor substrate under the transmitting electrode, based on the application of depleting voltage and heat transfer medium in the semiconductor substrate of the electric field, accelerating charge carrier in the transfer direction of the heat source. and in order to increase the speed, the transmitting electrode is formed as separate, parallel and perpendicular to the direction of transfer of charge carriers of the parts, the length of which s in carrier transport direction is less than the depth of field, prostran§ governmental charge and on different parts of one transmitting electrode fed (A rising in magnitude in a direction of transport capacity.

Description

The invention relates to the field of electronic engineering and can be used in information processing systems. A known method of creating a potential relief under the transmitting electrodes in devices with charge coupling (CCD) consists in aciiMmetric arrangement of implanted barriers under the electrodes, which are doped with the same type of alloyed substrate areas. These barriers separate charge nose charges. The disadvantages of this method are the low magnitude of the substrate carrier in the substrate along the transfer direction, which leads to a low speed of the device, the complexity of photolithography in the manufacture of the device, due to the need to accurately align the area of doping with the transmitting electrodes; limited height of potential relief under the electrodes. There is also known a method of creating a potential-like relief in a semiconductor substrate under a transmitting electrode, based on the application of a depleting voltage to a transmitting electrode and the formation of an accelerating electric field in a semiconductor substrate in the direction of transfer. This solution is with the closest to the invention according to. essence and the achieved result. The disadvantage of this method is a small field directed along the electrode, which leads to a lack of speed of the device. The aim of the invention is to increase speed. The goal is achieved by the fact that with the method of creating a potential relief in devices with charge coupling in a semiconductor substrate under the transmitting electrodes, deciding to apply depleting voltage to the transmitting electrode and forming an electric field in the semiconductor substrate accelerating the charge carriers in the direction transfer, the transmitting electrode is formed in the form of separate parallel and perpendicular to the direction of transfer of charge carriers of parts whose length in the direction of transfer carry The leu is less than the depth of the spatial charge region, and the potential in the direction of transfer increases in different parts of the same transmitting elec- trode. Figure 1 shows a method for creating a potential relief in a CCD; Fig. 2 shows diagrams of phase voltages. The method is carried out as follows. The transmitting electrodes of the CCD are made as separate parts 1, 2, 3, l, 2, 3 connected between themselves, for example, in capacitances, where. the overlapping capacitances C and Cj are not electroplated. The parts of electrodes 3 and 3 are supplied with depleting phase voltage F and F, while the potentials of the remaining parts of electrodes 1, 2 and 1, 2 are relative to the substrate 4, covered with dielectric 5, the thickness of which is the same, also taking certain values : will be determined by the overlap capacitances of Cd and C, as well as the capacitances of these parts relative to the substrate Cg and C (not shown in the drawing). The capacitance between the phase electrodes can be neglected. Considering the above, for the potential 1,. Of the electrodes 1 and 1 we will have. ,

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(1) parts of the potential and 2, respectively: Selection of the value, and at the same time the capacity of the ceiling, the sizes and the capacity C and C of parts 1, 2 and l, 2, relative to Spoons, you can adjust the value of the potentials Cf and Cf. In this case, the required profile of the SCR is provided under the transmitting electrodes. The number of parts of which the transmitting electrodes are composed may also be greater; in this case, the edge component of the EC layer in the substrate increases, which leads to an increase in the drift component of the charge transferred, this ultimately increases the speed. An example of a specific implementation. Transmitting evil: CCDs are made of 10 cm and a length of 1.2110 with a width of 5

g U / / L. electromilicate from polysilicon with a specific resistance of 50 Ω cm, using nepeKptavayuschih gaps of three parts, Capacity overlap C and C, are respectively 3.8 -10 and 3, F Tolprna dielectric 1200 A, The substrate is made of silicon CEF - 4.5. The amplitude of the phase voltages F | and F4, 20 V. The upper limiting frequency in these structures as compared with cont. role increased from 2.5 to 4.2-10 Hz, i.e. The device speed was increased by about 1.5 times. The magnitude of the dark currents in these structures was less than the control ones — on average, 50; -70 times and amounted to A per bit. The total number of operations in the manufacture of a CCD has been reduced by two. The proposed method has the following technical and economic advantages: a significant increase in the speed of devices, a decrease in dark currents, and an extension of the field of application of the device. The proposed invention can be useful in creating large information processing systems.

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Claims (1)

METHOD FOR CREATING A POTENTIAL RELIEF IN CHARGED COMMUNICATION INSTRUMENTS in a semiconductor substrate under a transmitting electrode, 'based on application of a depleting voltage and formations in a semiconductor substrate of an electric field accelerating charge carriers in the transfer direction, excluding join The reason is that, in order to increase the speed, the transmitting electrode is formed in the form of separate, parallel and perpendicular to the direction of transfer of charge carriers parts whose length in n in the direction of carrier transfer is less than the depth of the space-charge region, and a potential increasing in absolute value in the direction of transfer is supplied to different parts of a single transmitting electrode. SU. 865078> 865078 ϊ