受験番号：38IPE005
問１．

[0008]
Here, in a case of applying the blockchain as a virtual currency to a trace of acontract agreement, a problem is how to prove that the contents of the contract wereagreed between two or more parties. An e-signature scheme used in the blockchain of
the virtual currency is based only on an e-signature of the remittance source as describedabove and requires no e-signature of the remittance destination. Meanwhile, in a caseof a contract between two or more parties, the contract cannot be established by issuing
the contract unilaterally, and the agreement of all stakeholders being the parties to thecontract is required to be made. However, one transaction forming the blockchain onlyincludes an e-signature of the sender, and thus there is no trace of the agreement to thecontract by the receiver in the transaction.
[0009]As a simple solution to the above problem, for example, a method to include,
in one transaction, e-signatures of all stakeholders is conceivable. Virtual currencies use
a multi-signature mechanism. Such a mechanism allows an address to be created, theaddress requiring a certain number or more of e-signatures for the transaction to beapproved. However, the process of including a plurality of e-signatures in one
transaction is complicated, such as which e-signature is required in advance, how atransaction before its approval is shared between the stakeholders, and where a pluralityof private keys are collected for signing.

問２．

[0021]In a planar component arrangement such as a surface-mounted product, thewiring between components tends to be redundant, but in the RFID tag using themultilayer printed wiring board as in the present invention, the wiring length can beshortened using the interlayer of the multilayer board, allowing power loss due to wiring
resistance to be reduced. This allows the RFID tag 10 to be downsized and thecommunication performance to be maintained.
[0022]
Now, the data communication principle of the RFID tag 10 will be described.
When a radio wave is transmitted from an RFID reader/writer device (not illustrated) to
the RFID tag 10 in order to read/write identification data of the RFID tag 10, reflection
and interference occur in the radio wave because of the metal body 30 to which the RFID
tag 10 is attached. At this time, a surface wave is generated on a surface of the metal
body 30 where the radio wave has collided with, and the surface wave is collected to thefirst antenna circuit 16a by the dielectric action. The surface wave collected by the firstantenna circuit 16a is sent to the second antenna circuit 16b and the third antenna circuit
16c via the through hole 18, and a radio wave of a specific frequency resonates and isutilized. The resonant amplified radio wave of the specific frequency is sent the RFID
tag chip 14. The RFID tag chip 14 that has received the radio wave places the datastored in the RFID tag chip 14 on the radio wave to return the radio wave to the RFID
reader/writer device from the second antenna circuit 16b and the third antenna circuit 16c,
and the RFID reader/writer receives the returned radio wave, thereby completing the datacommunication. In other words, the first antenna circuit 16a is an antenna circuit for
capturing a surface wave generated on the metal body 30, and the second antenna circuit
16b and the third antenna circuit 16c are antenna circuits for resonating a radio wave
collected by the first antenna circuit 16a at a specific frequency and sending the radio
wave to the RFID tag chip 14, and for transmitting a radio wave with data in the RFID
tag chip placed on.
[0023]
Since the RFID tag 10 uses the metal body 30 as if it were an antenna circuit
for collecting a radio wave transmitted from the RFID reader/writer device, thecommunication gain is higher than a case where an object to be attached is a non-metalbody.

問３．

[Claim 1]
A semiconductor device comprising:a semiconductor substrate having a high impurity concentration;a parallel pn layer provided on a surface of the semiconductor substrate , the parallelpn layer including first-conductive-type semiconductor regions and second-conductivetype semiconductor regions that are arranged alternately;a second-conductive-type base region provided on a surface layer of the secondconductive type semiconductor region;a first-conductive-type source region provided on a surface layer of the secondconductive-type base region;a gate electrode provided on a gate oxide film on a surface of the parallel pn layer;
anda source electrode that is electrically connected to the first-conductive-type source
region and the second-conductive-type base region and that is provided away from thegate electrode, whereinthe semiconductor device includes an insulating film selectively provided between
the surface of the parallel pn layer and the gate electrode, the insulating film being thicker
than the gate oxide film,
a first area where the gate electrode covers a neck part, of the surface of the parallelpn layer, other than the second-conductive-type base region or the first-conductive-typesource region and a second area, of the first area, where the gate electrode covers theinsulating film satisfy
0.1 ≤ second area/first area ≤ 0.4,
in a direction orthogonal to interfaces between the first-conductive-typesemiconductor regions and the second-conductive-type semiconductor regions, aplurality of islands of the insulating film are provided on a surface of the neck part
between adjacent ones of the first-conductive-type semiconductor regions, andrespective different ones of the insulating film are provided to cover a plurality ofelectric field concentration regions generated between adjacent ones of the firstconductive-type semiconductor regions.